The Collaborative International Dictionary of English v.0.48:
Platitudinous \Plat`i*tu"di*nous\, a. Abounding in platitudes; of the nature of platitudes; uttering platitudes. -- Plat`i*tu"di*nous*ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
platitudinous adj 1: dull and tiresome but with pretensions of significance or originality; "bromidic sermons" [syn: bromidic, corny, platitudinal, platitudinous]