1610s, "make easy, render less difficult," from French faciliter "to render easy," from stem of Latin facilis "easy to do," from facere "to do" (from PIE root *dhe- "to set, put"). Related: Facilitated; facilitates; facilitating.
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).
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Harper, D. (n.d.). Etymology of facilitative. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/facilitative