Wiktionary
n. (context grammar English) The grammatical mood expressing an order (see jussive).
WordNet
n. a mood that expresses an intention to influence the listener's behavior [syn: imperative, jussive mood]
Wikipedia
The imperative is a grammatical mood that forms commands or requests, including the giving of prohibition or permission, or any other kind of advice or exhortation.
An example of a verb in the imperative mood is be in the English sentence "Please be quiet". Imperatives of this type imply a second-person subject (you); some languages also have first- and third-person imperatives, with the meaning of "let's (do something)" or "let him/her/them (do something)" (these forms may alternatively be called cohortative and jussive).
Imperative mood can be denoted by the glossing abbreviation . It is one of the irrealis moods.