to ward off attack from; guard against assault or injury (usually fol. by from or against )

The sentry defended the gate against sudden attack.

to maintain by argument, evidence, etc.; uphold

She defended her claim successfully.

to contest (a legal charge, claim, etc.).

Law . to serve as attorney for (a defendant)

He has defended some of the most notorious criminals.

to support (an argument, theory, etc.) in the face of criticism; prove the validity of (a dissertation, thesis, or the like) by answering arguments and questions put by a committee of specialists.

to attempt to retain (a championship title, position, etc.), as in a competition against a challenger.

Law . to enter or make a defense.

verb

abandon , attack , desert , leave , quit , relinquish , resign , surrender , deny , forsake , renounce

verb

avert , battle , beat off , bulwark , care for , cherish , conserve , contend , cover , entrench , espouse , fend off , fight , fight for , fortify , foster , garrison , guard , guard against , hedge , hold , hold at bay , house , insure , keep safe , look after , maintain , mine , nourish , oppose , panoply , preserve , prevent , provide sanctuary , repel danger , resist , retain , safeguard , save , screen , secure , shelter , shield , stave off , sustain , take in , uphold , war , ward off , watch , watch over , withstand , advocate , aid , apologize for , argue , assert , back , back up , bear one out , befriend , champion , come to defense of , cover for , endorse , exculpate , exonerate , explain , go to bat for * , guarantee , justify , plead , prove a case , put in a good word , rationalize , recommend , ride shotgun for , say in defense , second , speak up for , stand by , stand up for , stick up for , stonewall * , support , thump for , vindicate , warrant , protect , ward , apologize , contest , countenance , go to bat for , harbor , repel , wear