Kibosh has been a part of our language for almost two centuries, but its origin baffles etymologists. It was prominent enough in lower-class London speech to attract the attention of Charles Dickens, who used it in 1836 in an early sketch, but little else is certain. Claims were once made that it was Yiddish, despite the absence of a plausible Yiddish source. Another hypothesis points to Gaelic caidhp bháis—pronounced similarly to, and meaning, " coif of death"—explained as headgear a judge put on when pronouncing a death sentence, or as a covering pulled over the face of a corpse when a coffin was closed. But evidence for any metaphorical use of this phrase in Irish is lacking, and kibosh is not recorded as spoken in Ireland until decades after Dickens' use.

History and Etymology for kibosh

of obscure origin

Note: A number of etymologies are summarized by Anatoly Liberman in online postings to the OUPblog maintained by Oxford University Press ("Unable to put the kibosh on a hard word," May 19, 2010; "Monthly gleanings," July 28, 2010; "Three recent theories of 'kibosh'," August 14, 2013; "Etymology gleanings," November 29, 2017). The recent theories to which he alludes see the following as sources for kibosh: the heraldic term caboched, caboshed "(of an animal's head) borne full-face without the neck showing"; kibosh as a term for an iron bar used by clogmakers in the north of England (apparently first attested in 1860); Arabic kurbāj, kirbāj "whip, lash" and its source, Turkish kırbaç. The latter hypothesis is argued at length in a monograph by Gerald Cohen, Stephen Goranson and Matthew Little, Origin of Kibosh (Routledge, 2017), which also summarizes recently found antedatings to citations of the word in the Oxford English Dictionary (dating the word with certainty to 1834, and perhaps to 1830). Pace the authors' enthusiasm, the Arabic/Turkish origin is questionable: if Charles Dickens' 1835 recording of the word as "kye-bosh" accurately reflects the vowel and accent of the first syllable (according with the current pronunciation), the phonetic gap between the source and the English word is difficult to bridge; and the authors suggest no mechanism by which an assumed loanword from the eastern Mediterranean could have found its way into the speech of lower London social strata. Liberman may well be correct that "with the present evidence at our disposal, the chance of unearthing the origin of kibosh is vanishingly small."