1620s, from Latin iniunct-, past participle stem of iniungere "impose; attach to" (see injunction) + -ive. As a term in grammar, from 1910.
Entries linking to injunctive
injunction n.
early 15c., from Late Latin iniunctionem (nominative iniunctio) "a command," noun of action from past participle stem of Latin iniungere "impose, inflict, bring upon," literally "attach to," from in- "on" (from PIE root *en "in") + iungere "to join together," from nasalized form of PIE root *yeug- "to join."
-ive
word-forming element making adjectives from verbs, meaning "pertaining to, tending to; doing, serving to do," in some cases from Old French -if, but usually directly from Latin adjectival suffix -ivus (source also of Italian and Spanish -ivo). In some words borrowed from French at an early date it has been reduced to -y (as in hasty, tardy).