Pronunciation: (im-per'u-tiv),[key] —adj. 1. absolutely necessary or required; unavoidable: It is imperative that we leave. 2. of the nature of or expressing a command; commanding.
3. Gram.noting or pertaining to the mood of the verb used in commands, requests, etc., as in Listen! Go! Cf. indicative (def. 2), subjunctive (def. 1).
—n. 1. a command.
2. something that demands attention or action; an unavoidable obligation or requirement; necessity: It is an imperative that we help defend friendly nations. 3. Gram. a. the imperative mood.
b. a verb in this mood.
4. an obligatory statement, principle, or the like.