I saw a reference to a “dado” in a description of a painting and realized that, although I’d seen the word occasionally, I had no idea what it meant; fortunately the OED updated its entry in March 2016, so I can present an up-to-date report for those who are as vague about it as I. The senses:

1. Architecture. A flat-faced plain block forming the portion of a pedestal between the base and the cornice; the face of such a block; = die n.1 4a. Now somewhat rare.
1664 J. Evelyn Acct. Archit. in tr. R. Fréart Parallel Antient Archit. 124 [The Pedestal] is likewise call’d Truncus the Trunk..also Abacus, Dado, Zocco, &c.

2. Architecture and Interior Decorating. Originally: wooden panelling running along the lower part of the wall of a room, made to resemble a continuous pedestal, and typically reaching up to waist height; spec. the flat surface of the panelling between the skirting and the cornice. In later use more generally: the lower part of the wall of a room, typically reaching up to waist height, when decorated differently from the upper part. Cf. wainscot n. 2.
1741 B. Langley & T. Langley Builder’s Jewel iv. 21 To proportion the Tuscan Cornice to a Room of any Height. Divide the Height, from the Floor or Dado, in 5, and the upper 1 in 5.
1995 K. McCloud Techniques of Decorating (1998) 18/3 The high dado of wooden panelling and the parquet-effect wood floor combine to make a cradle of colour.

3. North American. Woodworking and Joinery.
a. A tool used for cutting a channel or slot across the grain in the face of a piece of wood, esp. to allow for the insertion of another piece of wood. Now rare.
1825 Providence (Rhode Island) Patriot 19 Oct. (advt.) Joiners’ and Carpenters’ Tools… Dados.

b. A channel or slot cut across the grain in the face of a piece of wood, into which the edge of another piece is fixed; = housing n.1 5.
1875 J. D. Edwards Carpenter’s Man. 90 The groove itself is also called a dado.
2012 Joinery Tips & Techniques i. 8/2 Rabbets, grooves and dados can be ‘through’ (run entirely across the board..), or stopped at either of both ends.

The sense in the passage I read (in the LRB) was clearly 2, whereas my wife (who, like me, is North American) knew only sense 3.b; like me, she found it odd that there were two such divergent senses as “the lower part of the wall of a room” and “a channel or slot cut across the grain in the face of a piece of wood, into which the edge of another piece is fixed,” and I wish they’d explained the sense development. At any rate, the etymology is interesting:

< Italian dado (in architecture) cubical block forming part of a pedestal (a1465), specific use of dado die, cube (see die n.1)

And here’s the etymology for die (from 1895):

Early Middle English , dee, plural dēs, dees, < Old French de (nominative singular and oblique plural 12–14th cent. dez), modern French , plural dés = Provençal dat, datz, Catalan dau, Spanish dado, Italian dado; in form < Latin datum, substantive use of datus, datum ‘given’, past participle of dare to give. It is inferred that, in late popular Latin, datum was taken in the sense ‘that which is given or decreed (sc. by lot or fortune)’, and was so applied to the dice by which this was determined. Latinized mediæval forms < Italian and French were dadus, decius.

If I’d known that a die was “what is given,” I’d forgotten it.


  1. Dado molding (moulding) is the usage I’ve heard the most, interior decorators use it either in England or the US and I’ve forgotten which; alhough if Kevin McCloud’s being cited (he’s on the telly in Britain) I suppose it’s England. It’s a word I encountered in my Classical Language of Architecture course in Arch school but few other places – along with cyma recta & cyma reversa, dentils and lots of other classical details – and as my teacher said at the time (1978) you cant expect architects to be articulate designers if they dont speak the (classical) language. Modernism, in the US first after WW2 and then when it revived, after Postmodernism, stopped teaching this. In my opinion it’s as if they stopped teaching Pathology in Med school. My daughter’s learning none of this at her Arch school. I see Batty Langley is cited. I’ve always loved his name. He was one of the classical pattern-book writers who were so useful for the Americans building in wood (it would be called timber in the UK) during the 18th & 19th centuries.

  2. l apologise it my comment is hard to follow. I find it hard to write on a telephone. I’m always worried I’ll lose the whole thing, like Trond did the other day.

  3. Now I come to think, The Classical Language of Architecture is a book by John Summerson.

  4. I knew that dado referred to something related to woodworking or carpentry. If I had thought about it for a while, I could probably have come up with the kind of groove that is cut in a certain kinds of picture frames to slot an edge of the picture into. I had no idea that the defining feature of a dado groove is that it is cross cut. Moreover, I too am surprised that there existing another meaning that is also related to woodworking, but which otherwise appears unrelated.

  5. l apologise it my comment is hard to follow.

    No, no, it’s very interesting — I knew you’d have things to say about this!

  6. It was worth it just for the name Batty Langley.

  7. Not sure how standard Italian “dato” (given) turned into “dado”.

    Is it dialectal thing?

  8. I would longshot that the sense-3a tool was originally used when fixing a dado rail, which compound is incidentally the only use of “dado” I knew of.

  9. Lars Mathiesen says

    Maybe dado was the lautgesetzliche form and dato was re-imported from Latin.

  10. PlasticPaddy says

    The development of past participle seems to be complicated; here info for venetian:

    (10) -ATU, -ATA > -àdo, -àda > -ào, -àa
    Dall’altro lato dobbiamo invece presupporre uno sviluppo diverso e parallelo (cfr.
    (11)) per il MS di tipo cantà:
    (11) -ATU > -AT > -à [see footnote 12]
    Footnote 12 Da non escludere il passaggio -ATU > -àdo > -ào > -à. Lo sviluppo apocopato è testimoniato, per il veneto
    occidentale, anche dalla II con. (es. tazù accanto a tazùo), ma non più dalla III, in cui il tipo dormì è caduto in
    disuso, in questa zona. I testi veronesi più antichi testimoniano la convivenza degli esiti -à(d)o, -ù(d)o, -ì(d)o con
    gli esiti apocopati -à, -ù, -ì. Ess.: àn servido a Deo […] le ae encoronae raine preciose elle sì sun clamade …
    Source: “Osservazioni sul participio passato in veneto”
    Roberta Maschi e Nicoletta Penello (Università di Padova)
    Link: › documenti

    I personally approve of the names Maschi (o) and Pen(n)ello and look forward to seeing their adventures in linguistic fumetti.

  11. Jen in Edinburgh says

    Even once you move on from ‘panelling on the lower part of a wall’ (which I think I’ve only seen in Victorian school buildings, with about 15 coats of institutional paint on top, and had no idea it had a posh name), to ‘the lower part of a wall decorated differently from the upper’, there’s still often a wooden rail between.

    So like mollymooly, I would guess that the link is with the woodwork rather than the wall itself – that the tool or the joint was commonly used in the panelling, or maybe that the groove made e.g. round a cabinet to fit in the shelves reminded people of the line on a wall.

  12. @mollymooly: I suspect you may be right. Affixing the wainscoting to a wooden wall is a situation where you might consistently need to cut a groove perpendicular to the grain. Wall paneling has the boards standing vertically, so if you need to cut a horizontal rabbet groove, marking the attachment point for the top of the dado, you are always going to be cutting across the grain.

  13. Charles Shere says

    But e.g. fitting a bottom to a drawer typically involves dados cut into the side pieces *with* the grain.

  14. In general, intervocalic voicing of voiceless stops is standard in the languages of northern Italy past the La Spezia–Rimini Line, and the preservation of voiceless stops in that position is usual in the southern languages, including Standard Italian.

  15. @Charles Shere: According to the OED definitions, those wouldn’t be dadoes.

  16. I’d never come across the distinction until now, but a dado is indeed crossgrain whereas the same cut along the grain is a groove.

    A dado near the edge of a board would have much less strength than a groove, which is why the latter is appropriate for the side of a drawer,

  17. Charles Shere says

    Depends on where you are, I guess: see 2:

    dado /ˈdeɪdəʊ /
    ▸ noun
    (plural dados)
    1 the lower part of the wall of a room, below about waist height, when decorated differently from the upper part.
    ▪ short for dado rail:
    dados were fixed to the wall to protect the plaster.
    2 North American a groove cut in the face of a board, into which the edge of another board is fixed:
    [as modifier] a dado joint.
    3 Architecture the part of a pedestal between the base and the cornice.
    – ORIGIN mid 17th century (denoting the main part of a pedestal, above the base): from Italian, literally ‘dice or cube’, from Latin datum ‘something given, starting point’ (see datum).

  18. Graham Asher says

    Many Victorian and Edwardian houses in England have dado rails. Quite often there is no actual dado, but different wallpaper or wall covering below and above the rail. For decorative purposes there are thus several sections, all of which might have different colours or patterns: skirting board, dado, dado rail, area above dado rail, picture rail, and area between picture rail and cornice.

    I was told (and this seems to be supported by the definition quoted by Charles Shere) that their purpose was to prevent wallpaper being torn when chairs were pushed back from the table after dinner, perhaps to allow expansive gestures over the brandy and cigars.

  19. Electric Dragon says

    Many years ago, I was working on a project to install new IT and hardware in some offices. One of the terms I encountered was “dado trunking” – plastic boxes at the height of the dado rail that extend along the length of a wall and conceal power and networking cables, with sockets for each at regular intervals.

  20. @Electric Dragon: Those are ubiquitous in American offices and especially scientific labs. They would be termed a type of “wall conduit.”

  21. Stu Clayton says

    This “conduit” business has been puzzling me for years – that is, what the English expressions are that correspond to German terms such as Brüstungskanal (the link contains pictures of what Brett calls “wall conduit in American offices and scientific labs”). There’s also the slightly more general Kabelkanal (pictures), which I suppose is also a type of “wall conduit”, but not restricted to horizonal at approx. waist height as is Brüstungskanal. What’s shown at the second link is Aufputzkabelkanäle, that is “surface mounted” (?) as opposed to “recessed” (?) conduits, running in all directions.

    All conduits, ducts, electrical switches and outlets can be Aufputz (“on the plaster”) or Unterputz (“beneath the plaster”). Is the English “surface/wall mounted” as opposed to “recessed” / “concealed” / “hidden” ?

    It’s curious that neither Pons nor Langenscheidt knows of Aufputz as something that can be rendered into English, except in the slightly antiquated sense of “exaggerated finery [that someone dolls themselves up with]”. Duden doesn’t even have the “mounting technique” meaning in German as a prefix, only the “finery” one that is not a prefix. Langenscheidt Ger/Eng has three words starting with Unterputz – for example, it says Unterputzleitung is a “concealed wire” or “buried wire”. But the general sense of Aufputz and Unterputz, which is familiar to every German I’ve ever met, seems to have gone missing. The German words speak for themselves.

  22. In English, “conduit” applies whether the configuration is inside the wall or outside. Different types can be clarified with additional descriptors: “metal conduit,” “ceiling conduit,” “external conduit,” “vertical conduit,” etc. Some of these may be terms of art, but it has been many years since I did a meaningful amount of cabling installation, and I am no longer familiar with the jargon (if I ever was; I honestly do not remember).

  23. Surface-mounted or wall-mounted are standard terms for what you call Aufputz. Recessed, AFAIK, is only used to describe outlets where the box is installed in the wall, so that the plate is flush with the wall. You wouldn’t talk about wiring or a conduit being recessed.

    As for Unterputz, I can’t think of a standard term in English that would apply. As it happens, my condo is 1940s construction, and some of the original wiring travels through metal tubing that’s buried in the plaster-and-lath walls. There’s no hollow space within the walls, as in modern drywall construction. I don’t know how to describe what I mean except to say what I just said.

  24. Stu Clayton says

    In English, “conduit” applies whether the configuration is inside the wall or outside.

    You wouldn’t talk about wiring or a conduit being recessed.

    But a “duct” can be recessed, or not ? Maybe not hidden from sight, but still not always wall-mounted or suspended from the ceiling ?

  25. Looked Russian technical dictionary. It gives that meaning of Aufputz as “otkrytaya prokladka(provodka)” (“open wiring, open assembly”)

    And Unterputz is “skrytaya prokladka(provodka)” (“concealed wiring, concealed assembly”)

  26. Stu Clayton says

    some of the original wiring travels through metal tubing that’s buried in the plaster-and-lath walls. There’s no hollow space within the walls, as in modern drywall construction.

    That too would simply be called an Unterputzkabelkanal, I think, no matter whether buried in the wall or laid in the hollow space. On tv I’ve seen someone milling a channel in a concrete wall in order to place a cabel conduit in it, then plaster it over.

  27. David Marjanović says

    It’s curious that neither Pons nor Langenscheidt knows of Aufputz as something that can be rendered into English, except in the slightly antiquated sense of “exaggerated finery [that someone dolls themselves up with]”.

    That’s the only sense I knew.

  28. Stu Clayton says

    Is there no corresponding terminology in Austrian German for how switches/wiring etc are installed ? Aufwändig, for example. 🙂 Or unterwand.

  29. But a “duct” can be recessed, or not ?

    Not sure, to be honest. Recessed outlets and switches and light fixtures are familiar to me, but recessed ductwork doesn’t sound quite right. But as I say, I don’t know what else I would call it.

    When the wiring is hidden from sight, no word to describe it is possible, as Wittgenstein mostly likely observed somewhere or other.

  30. Stu Clayton says

    Wovon man nicht sprechen kann, darüber muß man schweigen.

    As if ! That would dispose of 99% of talking. Just like

    Wovon man nichts sehen kann, darüber muß man schweigen

    in the present context. That hasn’t stopped any of us.

  31. There’s also the question of whether you say COND-it like an insider or CON-du-wit like the hoi polloi. I go with the latter, despite the obvious analogies of circuit, biscuit.

  32. Stu Clayton says

    COND-it like an insider

    Inside of what ? A sense deprivation chamber ?

  33. Insider to the profession of conduit-installation, -repair, -removal.

  34. I go with the latter

    Me too; the chances of being in conversation with someone who would understand the insider pronunciation are minimal, so what’s the point?

  35. Stu Clayton says

    Does this “insider” pronunciation COND-it actually exist, or is it the imaginary production of a strawman ?

  36. David Marjanović says

    Is there no corresponding terminology in Austrian German for how switches/wiring etc are installed ?

    I don’t know. 🙂

  37. In English, “conduit” applies whether the configuration is inside the wall or outside.

    No it doesn’t. In America, conduit is surface-mounted. What goes inside the walls is called bx (bee-eks); it’s a flexible metal spiral slightly less than 1″ dia. inside which the wire is threaded, as it is with conduit (there’s also nm cable now) you can see it here. Can you imagine how much work it would be to run rigid conduit with 45 and 90 degree corners up and down through all the stud walls? Ridiculous.

    In Europe a lot of wiring is surface-mounted, which is cheaper to install, has plastic surface-mtd junction boxes and ends up kind of old fashioned looking. I always hated it as a child for its messiness but now I rather like it, it least for buildings that are mine (I still would die rather than recommend it for something I’d designed). I used to be such a compulsively neat tightass but one loosens up aesthetically, with any luck, as one ages.

    COND-it like an insider
    As an insider, I can tell you that’s rubbish. It’s pronounced CON-do-it by every architect, lighting engineer and electrician I ever met.

    I’ve no time to read the whole thread now, but I’ll be back. 🙂

  38. The pronunciation “COND-it” certainly exists (or has existed); the only thing that could possibly be imaginary is the idea that it has or had a special status as an “insider” pronunciation. The Oxford English Dictionary lists “Brit. /ˈkɒnd(w)ɪt/, /ˈkɒndjʊɪt/, /ˈkʌndɪt/, /ˈkɒndɪt/, U.S. /ˈkɑnˌduət/, /ˈkɑndwət/”. The 1989 edition seems to have only listed “ˈkʌndɪt, ˈkɒndɪt”.

  39. @AJP Crown: What makes you think “conduit” cannot be flexible? The guys who were pulling new wires back inside the walls of my house definitely talked about “flexible conduit,” which sounds perfectly natural to me.

  40. I’ve always pronounced the word kon-dwit, two syllables.

    I replaced some of the wiring in my attic with bx — because of a perennial squirrel problem.

  41. The folks who sell BX (or some of them) call it “steel flexible conduit” so as not to genericize the trademark. However, it’s true that another generic name for it is “armored cable”. Its distinguishing mark is that the spiral armor is also the grounded (earthed) connection, which means it needs one less wire inside it.

    ObHat: It seems that mediaeval Latin musa ‘banana’ is < Arabic < Persian < Indian < early (but not Proto-) Dravidian < Eastern Austronesian < Proto-Trans–New Guinea *mugu, a pathway of 14,400 km and some 6500 years. Slides by Roger Blench.

  42. I’ve always pronounced the word kon-dwit, two syllables.
    So have I, but – and now I’m out of my professional comfort zone – are you sure dwit is one syllable? Isn’t it duh-wit, two?

    I replaced some of the wiring in my attic with bx — because of a perennial squirrel problem.
    That sounds sensible. Leaving bx exposed may not be allowed by US codes. I can’t remember. One reason might be that the wires are still exposed at the connections to the outlets & switches etc.

    spiral armor is also the grounded connection
    So nm doesn’t count (nm = non metal), but unless it’s changed nm is not to code in NYC, so no worries. Being metal, bx carries an electrical load to ground but it’s a backup rather than a dedicated ground circuit. Wiring regulations are incredibly complicated and detailed both in the NEC and in local codes.

    Retailers call it “steel flexible conduit”…“armored cable”
    And everyone in the trade calls it bx. I’ve never used it, but Brett has a good point that flexible conduit is a more descriptive phrase. The less jargon, the better.

    An important point about specialised electrical circuits is that tiny quantities of current often leak from the wiring. Although they aren’t dangerous the vibrations can put cows off their milking. We have a plug-in machine that sends a vibe through our wiring to annoy mice. Not that I specifically set out to annoy mice, it’s just to discourage them from living in the house – and it works.

  43. Roberto Batisti says

    Maybe dado was the lautgesetzliche form and dato was re-imported from Latin.

    It’s… complicated.

    North of the La Spezia-Rimini line, the lautgesetzlich outcome of Latin voiceless stops in intervocalic position is voiced, often with further lenition up to zero depending on dialect (see the Venetian examples in the paper quoted above). South of the line, voiceless stops are preserved at the phonemic level, even though they are often more or less synchronically lenited (but staying distinct from actual voiced stops). Notoriously, Tuscan has is own kind of allophonic lenition, not voicing but spirantization, the famous ‘gorgia toscana’.

    However, in Tuscan (> Standard Italian) voiced and voiceless stops coexist apparently at random (LOCU(M) > luogo ‘place’ but FOCU(M) > fuoco ‘fire’). This is an old problem of Romance linguistics. Voicing is often ascribed to contact with Northern dialects and Western Romance, both at the level of individual loanwords and of structural contact (voicing appears to have been extended to forms that were exclusive to Tuscan, or to contexts where it didn’t appear in the models, e.g. after AU). After all, the medieval Northern Tuscan dialects that Italian is based on were located just across the linguistic border. One weighty argument for non-native origin is that grammatical morphemes never show voicing: the past participle is always -ato -uto -ito . Other authorities prefer to explain the contradictory outcome as an internal development due to ‘resistance’ to voicing.

    And of course learnèd forms (re-)imported from Latin have no lenition at all.

    So, dato ‘given’ is fully native, dado ‘dice’ must be either an old loan from a Northern dialect or a native Tuscan form showing the alternative (Northern-influenced?) treatment, while dato ‘item of data, fact, evidence’ is a loan from Latin.
    And dato would be realized as [ˈdaːθo] in Tuscany, [ˈdaːd̥o] or the like in several Center-Southern accents and dialects, [‘daːto] in the standard and usually in Northern accents.

  44. Very interesting, thanks!

  45. NM (i.e. plastic-jacket) cable has actually been technically permitted in NYC since at least 1987, but since the NYC code at that time contained a whole list of circumstances in which it could not be used and none in which it could, the general assumption was that it was safer to avoid it. But since 2003 the code (which is now the NEC with local amendments) makes clear that NM is usable only in residential buildings with one to three stories. I doubt if there is any in Manhattan, but new construction in the boroughs may well contain it.

  46. For some reason I would have guessed /kɒnduːt/.

  47. David Marjanović says

    Like suit and fruit and many others.

  48. Monosyllabic ui is rare in English: in bruise, bruit, cruise, fruit, juice, nuisance, pursuit, recruit, sluice, suit it’s stressed and GOOSE, but most of the other cases are ones where u represents /w/ like liquid, linguini and those with gui, gue, cui where the u is a mere graphical sign that the previous g is /g/.
    Finally, there is build and its relatives, whose spelling is mysterious. In ME it was bilden, but for some completely unknown reason Caxton printed buyld and that stuck; the pronunciation is KIT as expected.

    Etymologically conduit < Fr. < L conductus, and only in this sense is the French spelling retained; otherwise conduct has completely displaced it. The OED1 reports both the alternative spelling cundit and the corresponding pronunciation with STRUT.

  49. for some completely unknown reason Caxton printed buyld and that stuck

    Must be one of those archaizing etymological spellings, based on the derivation from PIE *bʰuH- (:

    In contrast to the usual English spelling rule of ‹Vi› before consonant and ‹Vy› word-finally being equivalent, ‹uy› is however more often ᴘʀɪᴄᴇ than not.

  50. are you sure dwit is one syllable?

    I’ll settle for one and a half, although the professionals may not allow it.

  51. ‹uy› is however more often ᴘʀɪᴄᴇ than not.

    Eh, not much to compare them with: buy and guy and derivatives are probably all there are. Exceptions: words in -quy are FLEECE (or KIT where happy-tensing has not happened) because qu; syllable boundaries like gruyere, toluyl; phonetically unassimilated loans like guyot, fluyt.

  52. PlasticPaddy says

    Maybe jp means the pronunciation of (New York) names like Schuyler and Stuyvesant.

  53. In Hebrew, (אינטרפוץ)”interputz” specifically means a shower tap which is installed on the wall, separate from the shower head, and usually also having a switch between two outlets. I’m not sure what happened to the vowel on the way from German though

  54. David Marjanović says

    Litvak Yiddish consistently turns u into i, IIRC. Maybe that’s what happened.

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