Emily Dickinson Lexicon

IM-PER'A-TIVE, a. [Fr. imperatif; L. imperativus, from impero, to command. See Empire.]

1. Commanding; expressive of command; containing positive command, as distinguished from advisory, or discretionary. The orders are imperative.
2. In grammar, the imperative mode of a verb is that which expresses command, entreaty, advice or exhortation; as, go, write, attend.