Source : Webster's Revised Unabridged Dictionary (1913)

Polysyllabic \Pol`y*syl*lab"ic\, Polysyllabical
\Pol`y*syl*lab"ic*al\, a. [Gr. ?; poly`s many + ? syllable: cf.
   F. polysyllabique.]
   Pertaining to a polysyllable; containing, or characterized
   by, polysyllables; consisting of more than three syllables.