stultify -- (prove to be of unsound mind or demonstrate someone's incompetence; "nobody is legally allowed to stultify himself")
stultify -- (cause to appear foolish; "He stultified himself by contradicting himself and being inconsistent")
cripple, stultify -- (deprive of strength or efficiency; make useless or worthless; "This measure crippled our efforts"; "Their behavior stultified the boss's hard work")