to overcome in a contest, election, battle, etc.; prevail over; vanquish

They defeated the enemy. She defeated her brother at tennis.

to frustrate; thwart.

to eliminate or deprive of something expected

The early returns defeated his hopes of election.

Law . to annul.

the act of overcoming in a contest

an overwhelming defeat of all opposition.

an instance of defeat; setback

He considered his defeat a personal affront.

an overthrow or overturning; vanquishment

the defeat of a government.

a bringing to naught; frustration

the defeat of all his hopes and dreams.

the act or event of being bested; losing

Defeat is not something she abides easily.

Archaic . undoing; destruction; ruin.

noun

conquest , success , triumph , victory , win , attainment , mastery

verb

give up , lose , surrender , abet , aid , encourage , help , inspirit

noun

ambush , annihilation , beating , blow , break , breakdown , check , collapse , conquest , count , debacle , defeasance , destruction , discomfiture , downthrow , drubbing , embarrassment , extermination , failure , fall , insuccess , killing * , ko , lacing , licking , loss , massacre , mastery , nonsuccess , paddling , rebuff , repulse , reverse , rout , ruin , scalping , setback , shellacking , slaughter , subjugation , thrashing , trap , trashing , trimming , triumph , trouncing , vanquishment , waxing , whaling , whipping , whitewashingnotes:decimate means to kill or destroy in large numbers; defeat means to win a victory over or to beat , disappointment , downfall , foil , reversal , thwartingnotes:decimate means to kill or destroy in large numbers; defeat means to win a victory over or to beat , overthrow , bouleversement , frustration , labefaction , waterloo

verb

ambush , annihilate , bar , bear down , beat , best , block , butcher , crush , decimate , demolish , discomfit , drown , entrap , finish off , halt , hinder , impede , lick , mow down , obliterate , obstruct , outflank , outmaneuver , overpower , overrun , overthrow , overwhelm , parry , prevail over , quell , reduce , repel , repress , repulse , roll back , rout , route , sack , scatter , shipwreck , sink , slaughter , smash , subdue , subjugate , suppress , surmount , swamp , torpedo * , trample , trash , upset , vanquish , whip , wipe outnotes:decimate means to kill or destroy in large numbers; defeat means to win a victory over or to beat , bust * , clobber * , cream * , deck * , drop * , drub * , edge , flax , flog * , floor * , knock out * , ko , lambaste * , outhit , outjump , outplay , outrun , plow under , pommel * , pound * , powder * , pulverize * , run roughshod over , skin * , steamroll , take , take it all , take to cleaners , tan * , thrash , total , trounce , wallop * , whack * , whomp , win , work over , zap *notes:decimate means to kill or destroy in large numbers; defeat means to win a victory over or to beat , baffle , balk , beat down * , beat the system , blank , bury , cast down , cause setback , checkmate , circumvent , confound , contravene , cook * , counterplot , cross , disappoint , disconcert , disprove , edge out * , foil , invalidate , neutralize , nonplus , nose out * , nullify , outwit , overturn , put end to , puzzle , refute , ruin , scuttle , shave * , shellac * , skunk * , spoil , squash , stump , take wind out of sails , throw for loop , thwart , undo , victimizenotes:decimate means to kill or destroy in large numbers; defeat means to win a victory over or to beat , conquer , master , overcome , prevail against , triumph over , worst , check , stymie , break , crucify , defeasance , deprive , destroy , devastate , eclipse , excel , floor , frustrate , loss , outperform , outshine , overreach , prevail , pulverize , reverse , setback , shellac , surpass , thwack , triumph