The Collaborative International Dictionary
Trisyllabically
Trisyllabic \Tris`yl*lab"ic\, Trisyllabical \Tris`yl*lab"ic*al\, a. [L. trisyllabus, Gr. ?; ? (see Tri-) + ? a syllable: cf. F. trissyllabique.] Of or pertaining to a trisyllable; consisting of three syllables; as, ``syllable'' is a trisyllabic word. -- Tris`yllab"ic*al*ly, adv.
Wiktionary
trisyllabically
adv. In three syllables.