imperative² n [C] 1 something that must be done urgently 急切要做的事: Reducing pollution has become an imperative. 减少污染已成为当务之急。 2 the form of a verb that expresses a command. In "Do it now!" the verb 'do' is in the imperative. 祈使语气(动词)〔如在 Do it now! 中,动词 do 即为祈使语气〕