contradict (v.)

1570s, "speak against, oppose" (a sense now obsolete); 1580s, "assert the contrary or opposite of," from Latin contradictus, past participle of contradicere, in classical Latin contra dicere "to speak against," from contra "against" (see contra (prep., adv.)) + dicere "to say, speak" (from PIE root *deik- "to show," also "pronounce solemnly").

Meaning "deny the words or assertions of, speak in contradiction" is from c. 1600. Of statements, etc., "be inconsistent with," c. 1600. Related: Contradicted; contradicting; contradictive.