Entry 1 sense Webster, 1913 Platitudinous · Plat·i·tu·di·nous · IPA /ˌplætɪˈt(j)ud(ə)nəs/ 01 a. Abounding in platitudes; of the nature of platitudes; uttering platitudes. 1. Abounding in platitudes; of the nature of platitudes; uttering platitudes.