kibosh UK /ˈkaɪˌbɒʃ/US /ˈkaɪˌbɑʃ/noun 2verb 1forms 3 noun2 •(slang, no longer used) Bosh, nonsense.Gar'n! Gives me the 'ump, all this kibosh 'bout morals, and taste, and all that. — 1887 •(slang, no longer used) Chiefly preceded by the: fashion, style.She was, in very Sooth, among the highest of the Rollers, but Hiram stood for the Bills with nary a Whimper. He was proud to be the Husband of the Lady Ki-Bosh of the Local Knickerbockers. — 1904 verb1 •(slang) To decisively put a stop to or terminate (someone or something).His second book is full of spirited advice on how to do business deals. According to [Mark] McCormack, this often amounts to keeping lawyers from kiboshing the deal. — 1987 formskiboshed · kiboshing · kiboshes