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