defy definition, defy meaning | English dictionary. Search also in: Web News Encyclopedia Images. defy. vb , -fies, -fying, -fied tr. 1 to resist (a powerful person, authority, etc.) openly and boldly. 2 to elude, esp. in a baffling way. his actions defy explanation. 3 Formal to challenge or provoke (someone to do something judged to be impossible); dare. I defy you to climb that cliff. 4 Archaic to invite to do battle or combat.