convince (v.) Look up convince at Dictionary.com
1520s, "to overcome in argument," from Latin convincere "to overcome decisively," from com-, intensive prefix (see com-), + vincere "to conquer" (from nasalized form of PIE root *weik- (3) "to fight, conquer"). Meaning "to firmly persuade" is from c. 1600. Related: Convinced; convincing; convincingly.