openly refusing to obey somebody/something, sometimes in an aggressive way a defiant teenager The terrorists sent a defiant message to the government.Word Familydefy verbdefiance noundefiant adjective Word Origin late 16th cent.: from French défiant or directly from defiance.Extra examples He had a slightly defiant air. Sylvia tossed back her dark hair in a gesture that was openly defiant. He was in a defiant mood, unwilling to give way to anyone. She had suddenly turned into a defiant teenager.