Entry 1 sense Webster, 1913 Iconoclastic /īkˌ-ən-ək-lăs'-tĭk/ · I·con·o·clas·tic · IPA /ˌaɪkənəklˈæstɪk/ 01 a. Of or pertaining to the iconoclasts, or to image breaking. 1. Of or pertaining to the iconoclasts, or to image breaking.