imperative Definition

imperative
adj

1. Absolutely essential; urgent.

Example: It is imperative that we act at once
Thesaurus: necessary, requisite, mandatory, immediate, inescapable, urgent, crucial; Antonym: optional.
2. Having or showing authority; commanding.

Example: At meetings his manner is imperative, never conciliatory
Thesaurus: authoritative, commanding, dominant, masterful.
3. grammar.
Said of the mood² of a verb: used for giving orders.

noun

1. grammar.
A set of verb forms, or mood, used for giving orders, eg ‘Listen to me' and ‘Do as I say!'. Compare indicative, conditional, subjunctive.
2. A verb form of this kind.
3. Something which is imperative, especially a command or order.

Thesaurus: duty, obligation, commandment, order, requirement, necessity.

Derivative: imperatively
adverb

Etymology: 16c: from Latin imperativus, from imperare to command.