stultify

verb

1. 1

   deprive of strength or efficiency; make useless or worthless

   This measure crippled our efforts

   Their behavior stultified the boss's hard work

2. 2

   cause to appear foolish

   He stultified himself by contradicting himself and being inconsistent

3. 3

   prove to be of unsound mind or demonstrate someone's incompetence

   nobody is legally allowed to stultify himself