1. (v. t.) To revoke (a former command); to cancel or rescind by giving an order contrary to one previously given; as, to countermand an order for goods.

2. (v. t.) To prohibit; to forbid.

3. (v. t.) To oppose; to revoke the command of.

4. (n.) A contrary order; revocation of a former order or command.

abolish abolishment abolition abrogate abrogation annul annulment baffle balk blast brave cancel canceling cancellation cassation challenge checkmate circumvent confound confront contravene counter counteract counterorder counterwork cross dash defeasance defeat defy destroy disannul discomfit disconcert discountenance dish disrupt do away with elude flummox foil frustrate invalidate invalidation knock the chocks make void nonplus nullification nullify override overrule perplex recall recant recantation renege repeal rescind rescinding rescindment rescission retract retraction reversal reverse revocation revoke revokement ruin sabotage scotch set aside setting aside spike spoil stonewall stump suspend suspension thwart upset vacate vacation vacatur void voidance voiding waive waiver waiving withdraw withdrawal write off write-off