A question from dearieme in this thread sent me to the OED’s new draft revision (Sept. 2010) of the etymology of posh, a perennial favorite of folk etymologists (no, it’s not from “port outward, starboard home,” and I’m surprised the OED dignifies that old wheeze with an entire paragraph):
It is possible that the word arose as a transferred use of POSH n.1 [‘halfpenny,’ from Romani], POSH n.3 [‘a dandy,’ origin unknown] (compare quot. 1912 at POSH n.3 [“If he described another [tailor] as a great ‘posh,’ which means well-dressed, the whistle would place him in a.. ridiculous light”]), or both of these; the semantic development may thus have been either from ‘money’ to ‘moneyed, wealthy’, and hence to ‘upper-class’ and ‘smart, stylish, luxurious’, or alternatively from ‘dandy’ to ‘upper-class‘ and ‘smart, stylish, luxurious’.
An alternative suggestion derives the word < Urdu safed-pōś dressed in white, well-dressed, also used as a colloquial and derogatory term for ‘affluent’ < safed white (safed (Old Persian saped)) + pōś covering, also ‘clothed in, wearing’ (< Persian pōś: see PAPOOSH n.). However, this poses phonological problems and there is no direct evidence for the transition into English.
A popular explanation (still frequently repeated) is that the word is < the initial letters of the phrase port outward, starboard home, with reference to the more comfortable (because cooler) and more expensive side for accommodation on ships formerly travelling between Britain and India. It is often suggested that the Peninsular & Oriental Steam Navigation Company stamped tickets for such cabins on this route with the letters P.O.S.H., whence the word. However, no evidence has been found for the existence of such tickets. See further G. Chowdharay-Best in Mariner’s Mirror (1971) Jan. 91-2.
It is unclear whether the following shows an (earlier) variant of this word:
1903 P. G. WODEHOUSE Tales of St. Austin’s 37 That waistcoat.. being quite the most push thing of the sort in Cambridge.
If you’re curious, as I was, about “PAPOOSH n.,” it’s “A Turkish or Middle Eastern slipper, usually made of soft leather” and comes from French papouch < Turkish pabuç shoe, slipper < early modern Persian pāpōš < pā foot + pōš (modern Iranian Persian pūš) ‘cover, covering.’ I wonder why they decided to change from ś to š for the same Persian sound between Dec. 2007 and Sept. 2010?