absolutely necessary or required; unavoidable: It is imperative that we leave.
2.
of the nature of or expressing a command; commanding.
3.
Grammar. noting or pertaining to the mood of the verb used in commands, requests, etc., as in Listen! Go! Compare indicative( def 2 ), subjunctive( def 1 ).
noun
4.
a command.
5.
something that demands attention or action; an unavoidable obligation or requirement; necessity: It is an imperative that we help defend friendly nations.
Origin: 1520–30; < Late Latinimperātivus, equivalent to Latinimperāt(us) past participle of imperāre to impose, order, command (im-im-1 + -per- (combining form of parāre to fur-nish (with), produce, obtain, prepare) + -ātus-ate1) + -īvus-ive
peremptory or authoritative: an imperative tone of voice
3.
grammar Also: imperatival denoting a mood of verbs used in giving orders, making requests, etc. In English the verb root without any inflections is the usual form, as for example leave in Leave me alone
—n
4.
something that is urgent or essential
5.
an order or command
6.
grammar
a. the imperative mood
b. a verb in this mood
[C16: from Late Latin imperātīvus, from Latin imperāre to command]
1530, from L.L. imperativus "pertaining to a command," from imperatus "commanded," pp. of imperare "to command, to requisition," from in- "in" + parare "beget, bear" (see pare).