decasyllabic

from WordNet (r) 3.0 (2006)

decasyllabic
    adj 1: having or characterized by or consisting of ten syllables

from The Collaborative International Dictionary of English v.0.48

Decasyllabic \Dec`a*syl*lab"ic\, a. [Pref. deca- + syllabic: cf.
   F. d['e]casyllabique, d['e]casyllable.]
   Having, or consisting of, ten syllables.
   [1913 Webster]