invalidate


invalidate (http://definr.com/invalidate)

     v 1: declare invalid; "The contract was annulled"; "avoid a plea"
          [syn: annul, quash, void, avoid, nullify]
          [ant: validate]
     2: of cheques or tickets [syn: cancel]
     3: show to be invalid [syn: nullify] [ant: validate]
     4: take away the legal force of or render ineffective;
        "invalidateas a contract" [syn: void, vitiate] [ant: validate]