late Middle English (as a grammatical term): from late Latin imperativus (literally 'specially ordered', translating Greek prostatikē enklisis 'imperative mood'), from imperare 'to command', from in- 'toward' + parare 'make ready'
The imperative is the form of the verb used to make commands:“Go away!” cried Mary. It consists of the stem of the verb. Imperative clauses have a special form. They resemble a normal clause, but there is no subject. In effect the subject is you, but it is not stated:“(You) go away!” cried Mary.