Perhaps more widely known from the First World War song, Who Put the Kibosh on the Kaiser? To put the kibosh on someone is slang for to ruin, finish them off, or do for them and originated in Britain during the early 19th century. Charles Dickens used the expression in Sketches by Boz (1836) “Put the kye-bosh on her, Mary!” The exact etymology, however, remains unknown. There are many candidate theories varying from the Turkish bosh meaning empty, to the Gaelic caip bhais meaning black cap which the judge puts on before passing the death sentence. Others maintain it is of Yiddish or Scots origin but no one really knows for sure and, until more evidence comes to hand, the origin remains unknown. The OED also has kibosh as meaning nonsense or rot from 1873.