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late 14c., "unconnected, unrelated, not to the point," from Old French impertinent (14c.) or directly from Late Latin impertinentem (nominative impertinens) "not belonging," literally "not to the point," from assimilated form of Latin in- "not, opposite of" (see in- (1)) + pertinens (see pertinent). Sense of "rudely bold" is 1680s, from earlier sense of "not appropriate to the situation," probably modeled on similar use in French, especially by Molière, from notion of meddling with what is beyond one's proper sphere.