Source : Webster's Revised Unabridged Dictionary (1913)

Kosher \Ko"sher\, n.
   Kosher food; also, a kosher shop.

Kosher \Ko"sher\, v. t. [imp. & p. p. {Koshered}; p. pr. & vb.
   n. {Koshering}.]
   To prepare in conformity with the requirements of the Jewish
   law, as meat.

Kosher \Ko"sher\, a. [heb. kosh["e]r fit, proper.]
   Ceremonially clean, according to Jewish law; -- applied to
   food, esp. to meat of animals slaughtered according to the
   requirements of Jewish law. Opposed to {tref}. Hence,
   designating a shop, store, house, etc., where such food is
   sold or used.

Source : WordNet®

kosher
     adj 1: conforming to dietary laws; "kosher meat"; "a kosher
            kitchen" [syn: {cosher}]
     2: proper or legitimate
     n : food that fulfills the requirements of Jewish dietary law