The Collaborative International Dictionary
Quadrisyllabic
Quadrisyllabic \Quad`ri*syl*lab"ic\, Quadri-syllabical \Quad`ri-syl*lab"ic*al\, Having four syllables; of or pertaining to quadrisyllables; as, a quadrisyllabic word.
Wiktionary
quadrisyllabic
a. Having four syllables.