kosher

Definitions

Food

  • Food slaughtered and/or prepared according to the strict Jewish dietary laws

Slang

  • adjective correct, proper, above-board. This Yiddish term (usually referring to food prepared according to Talmudic law) is originally from the Hebrew kasher, meaning fitting or proper. The word was adopted in the late 19th century by non-Jewish speakers, particularly in the underworld, market trading or other raffish contexts. By the 1970s kosher was generally understood and used by speakers from a wide variety of backgrounds.
http://www.dictionarycentral.com/definition/kosher.html