overwhelm

[1]	overpower , overpower , sweep over , overcome , overtax , whelm , overcome , devastate , stagger , overtake , crush , defeat , destroy , subdue , suppress , quash , quell , conquer , beat , bring down , prostrate , weigh down , oppress
[2]	inundate , deluge , flood out , overcome , engulf , submerge , flood (over) , deluge , swamp , bury , immerse
[3]	overcome , submerge , drown , stagger , astound , astonish , dumbfound/dumfound , shock , stun , bewilder , confuse , confound , nonplus , surprise , take aback , (Colloq) bowl over , knock off one's feet/pins , blow one's mind , discombobulate , (Brit) knock for six
[4]	overpower , overmaster