frustrate

[1]	thwart , thwart , queer , foil , stymie , spoil , scotch , block , baffle , foil , cross , check , balk/baulk , baffle , bilk , disappoint , discourage , forestall , prevent , stop , halt , cripple , hinder , hamper , impede , hamstring , defeat , counteract , neutralize , nullify , counter , fight off , repel , repulse
[2]	discourage , torment , rag , disappoint , upset , bedevil , crucify , exasperate , dun