frustrate in WordNet English dictionary

1. hinder or prevent (the efforts, plans, or desires) of
   "What ultimately frustrated every challenger was Ruth's amazing September surge"; "foil your opponent"
   thwart  queer  spoil  scotch  foil  cross  frustrate  baffle  bilk 
   
2. treat cruelly
   "The children tormented the stuttering teacher"
   torment  rag  bedevil  crucify  dun  frustrate