Expressing command; containing positive command; peremptory; absolute: as, imperative orders.
Not to be avoided or evaded; that must be attended to or performed; obligatory; binding: as, an imperative duty or necessity.
noun.
In grammar, a mode or verbal form which expresses command, entreaty, advice, or exhortation.
noun.
In philosophy, a deliverance of conscience; a monition of the moral sense.