1690s, "applicable," from Latin apposit-, past participle stem of apponere "set near, set before; apply, give in addition; appoint, designate" (see apposite) + -ive. As a noun in grammar, "words in apposition," from 1847.
1620s, "well-put or applied, appropriate," from Latin appositus, adpositus "contiguous, neighboring;" figuratively "fit, proper, suitable," past participle of apponere "lay beside, set near," especially "serve, set before," also "put upon, apply," from ad "to, toward" (see ad-) + ponere "to place" (past participle positus; see position (n.)).
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 appositive. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/appositive