The Collaborative International Dictionary of English v.0.48:

Kibosh \Ki"bosh\, n.
   1. Nonsense; stuff; also, fashion; style. [Slang]
      [Webster 1913 Suppl.]

   2. Portland cement when thrown or blown into the recesses of
      carved stonework to intensify the shadows.

   To put the kibosh on, to dispose of; to squelch; to
      terminate; put an end to; to do for. [Slang]
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

kibosh
    v 1: stop from happening or developing; "Block his election";
         "Halt the process" [syn: stop, halt, block, kibosh]