overwhelm in WordNet English dictionary

1. charge someone with too many tasks
   overwhelm  deluge  flood out 
   
2. cover completely or make imperceptible
   "I was drowned in work"; "The noise drowned out her speech"
   submerge  drown  overwhelm 
   
3. overcome, as with emotions or perceptual stimuli
   overwhelm  overpower  sweep over  whelm  overcome  overtake 
   
4. overcome by superior force
   overpower  overmaster  overwhelm