The Collaborative International Dictionary
jussive
jussive \jus"sive\, a. (Grammar) Indicating or expressive of a mild command; as, the jussive case. -- n. The jussive case; a jussive mood, form, word, or construction.
Douglas Harper's Etymology Dictionary
jussive
"grammatical mode expressing command," 1846, from Latin iuss-, past participle stem of iubere "to bid, command," from PIE *yeudh- "to move violently, fight;" + -ive.
Wiktionary
jussive
a. (context grammar of a verb English) Inflected to indicate commands, permission or agreement with a request. n. (context grammar uncountable and countable English) The jussive mood, a verb inflection used to indicate a command, permission or agreement with a request; an instance of a verb so inflected.