Entry 1 sense Webster, 1913 Defiant /dĭf-ī'-ənt/ · De·fi·ant · IPA /dɪˈfaɪənt/ 01 a. Full of defiance; bold; insolent; as, a defiant spirit or act. 1. Full of defiance; bold; insolent; as, a defiant spirit or act. “In attitude stern and defiant.” — Longfellow.