Over a decade ago, I posted about the UK slang term oik (“Etym. obscure”), “Depreciatory schoolboy word for a member of another school; an unpopular or disliked fellow-pupil. Also gen., an obnoxious or unpleasant person; in weakened senses, a ‘nit-wit’, a ‘clot’.” Last night, as I was reading Anthony Powell to my wife (we’ve just started Books Do Furnish a Room, for which phrase see this post from last year; the setting is immediately after World War II), I hit this sentence (in the middle of a passage of heavily italicized babbling by Mona — sample: “We’re weaving about fairly close here, and I’ve got to scamper home this minute, because Jeff’s quite insane about punctuality”): “That erk will have to drive like stink if I’m not to be late.” My first thought was of oik, which would seem to fit equally well in this context, but there didn’t seem to be any way to connect the two in UK English (as opposed to the New Orleans or Brooklyn varieties), so I set it aside for investigation when I was up and about and rummaging in reference works. Now that that is the case, I can provide the OED entry (from 1972):
Etymology: Of obscure origin.
a. A naval rating.
b. An aircraftman, esp. an A.C.2.
c. transf. Used as a term of contempt.
1925 E. Fraser & J. Gibbons Soldier & Sailor Words 89 Erk, a rating. (Navy). Lower deck colloquialism for any ‘rank’ not that of an officer.
1928 T. E. Lawrence Let. 20 Jan. (1938) 570 Cranwell, which was a home from home, for the irks.
1940 Reader’s Digest May 31/2 The aviators..call their mechanics erks, apparently a corruption of A.C., the abbreviation for aircraftsman.
1943 P. Brennan et al. Spitfires over Malta iii. 65 The erks came running up to tell us that..the 109 had been diving down.
1944 E. Partridge in 19th Cent. Apr. 182 An erk, now used for an A.C.2..meant an air mechanic. This odd word is, the writer believes, a shortened pronunciation of the italicised letters in air mechanic (perhaps in the form of ‘air mech’)… Some airmen less convincingly maintain that it comes from ‘lower-deck hand’.
1959 I. Opie & P. Opie Lore & Lang. Schoolchildren x. 175 Somebody they dislike..may be called..erk, gawp, kid.
Interesting that these very similar words of equally obscure origin are both first attested in 1925 (though I imagine a little rooting about in Google Books and databases could antedate that); I also call attention to Eric Partridge’s typically clueless approach to etymology.