defamation (n.)

c. 1300, defamacioun, "disgrace, dishonor, ill repute" (senses now obsolete), from Old French diffamacion and directly from Medieval Latin deffamation, from Latin diffamationem (nominative diffamatio), noun of action from past-participle stem of diffamare "to spread abroad by ill report, make a scandal of," from dis-, here probably suggestive of ruination, + fama "a report, rumor" (from PIE root *bha- (2) "to speak, tell, say").

From late 14c. as "the wrong of injuring another's reputation without justification." From early 15c. as "calumny, slander, an instance of defaming."