Source : Webster's Revised Unabridged Dictionary (1913)

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

Source : WordNet®

platitudinarian
     n : a bore who makes excessive use of platitudes