"serving to instruct or inform," 1610s, from instruct (v.) + -ive. An earlier adjective was instructing (1580s). Related: Instructively; instructiveness.
Entries linking to instructive
instruct v.
early 15c., "to tell, inform, impart knowledge or information," also "furnish with authoritative directions," from Latin instructus, past participle of instruere "arrange, prepare, set in order; inform, teach," literally "to build, erect," from in- "on" (from PIE root *en "in") + struere "to pile, build" (from PIE *streu-, extended form of root *stere- "to spread"). Related: Instructed; instructing.
-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).