platitudinarian

from WordNet (r) 3.0 (2006)

platitudinarian
    n 1: a bore who makes excessive use of platitudes

from The Collaborative International Dictionary of English v.0.48

Platitudinarian \Plat`i*tu`di*na"ri*an\, n.
   One addicted to uttering platitudes, or stale and insipid
   truisms. "A political platitudinarian." --G. Eliot.
   [1913 Webster]