1520s, from Middle French imminent (14c.) and directly from Latin imminentem (nominative imminens) "overhanging; impending," present participle of imminere "to overhang, lean towards," hence "be near to," also "threaten, menace, impend, be at hand, be about to happen," from assimilated form of in- "into, in, on, upon" (from PIE root *en "in") + -minere "jut out," which is related to mons "hill" (from PIE root *men- (2) "to project"). Related: Imminently.