defy in WordNet English dictionary

1. challenge
   "I dare you!"
   defy  dare 
   
2. resist or confront with resistance
   "The politician defied public opinion"; "The new material withstands even the greatest wear and tear"; "The bridge held"
   defy  withstand  hold  hold up 
   
3. elude, especially in a baffling way
   "This behavior defies explanation"
   defy  resist  refuse