mid-15c., "projecting, jutting out," from Latin prominentem (nominative prominens) "prominent," present participle of prominere "jut or stand out, be prominent, overhang," from pro "before, forward" (see pro-) + -minere "project, jut out," which is related to mons "hill" (from PIE root *men- (2) "to project"). Meaning "conspicuous" is from 1759; that of "notable, leading" is from 1849. Related: Prominently.