mid-15c., from Old French inciter, enciter "stir up, excite, instigate" (14c.), from Latin incitare "to put into rapid motion," figuratively "rouse, urge, encourage, stimulate," from in- "into, in, on, upon" (from PIE root *en "in") + citare "move, excite" (see cite). Related: Incited; inciting.
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 incitive. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/incitive