platitudinous UK /ˌplætɪˈtjuːdɪnəs/US /ˌplætɪˈt(j)ud(ə)nəs/ adjective1 •Characterised by clichés or platitudes.“House Decoration” is written with somewhat less verbosity and with a good deal more taste and common sense. But it is, however detailed in its suggestions, equally platitudinous where it is sensible. — 1877 formsmore platitudinous · most platitudinous