1) Contradict 2) Query at a mattress factory 3) Repudiate 4) Reverse 5) To annul 6) To deny 
• (v. t.) To assert the contrary of; to contradict; to deny; -- said of that which has been asserted. • (v. t.) To refuse to confirm; to annul, as a judicial decision, by a contrary judgment of a superior tribunal.
Dis`af·firm' transitive verb 1. To assert the contrary of; to contradict; to deny; -- said of that which has been asserted. 2. (Law) To refuse to confirm; to annul, as a judicial decision, by a contrary judgment of a superior tribunal. 
to deny; contradict. · to annul; reverse; repudiate.