to overcome completely in mind or feeling

overwhelmed by remorse.

to overpower or overcome, esp. with superior forces; destroy; crush

Roman troops were overwhelmed by barbarians.

to cover or bury beneath a mass of something, as floodwaters, debris, or an avalanche; submerge

Lava from erupting Vesuvius overwhelmed the city of Pompeii.

to load, heap, treat, or address with an overpowering or excessive amount of anything

a child overwhelmed with presents; to overwhelm someone with questions.

to overthrow.

verb

underwhelm , not impress

verb

bury , conquer , crush , defeat , deluge , destroy , drown , drub * , engulf , inundate , massacre , overcome , overflow , overpower , overrun , overthrow , rout , smother , submerge , swamp , thrash , total * , whip * , win * , bewilder , blow out of the water , bowl over * , confound , confuse , demoralize , disturb , do in * , downgrade * , dumbfound , floor * , kill * , prostrate , puzzle , render speechless , run circles around , shatter , shock , stagger , steamroller , stun , subordinate , surprise , upset , wreck , flush , whelm , annihilate , drub , smash , trounce , vanquish , ruin , amaze , astonish , demolish , devastate , engross , floor , ingulf , oppress , overturn , sink , steamroll , whip