I. ˈkō-shər adjective
Etymology: Yiddish, from Hebrew kāshēr fit, proper
Date: 1851
1.
a. : sanctioned by Jewish law ; especially : ritually fit for use
kosher meat
b. : selling or serving food ritually fit according to Jewish law
a kosher restaurant
2. : being proper, acceptable, or satisfactory
made sure the deal was kosher
II. transitive verb
( ko·shered ; ko·sher·ing -sh(ə-)riŋ)
Date: 1871
: to make kosher
III. noun
Date: 1886
: the observance of kosher practices
keep kosher