The Collaborative International Dictionary
Tetrasyllabic
Tetrasyllabic \Tet`ra*syl*lab"ic\, Tetrasyllabical \Tet`ra*syl*lab"ic*al\, a. [Cf. F. t['e]trasyllabique.] Consisting of, or having, four syllables; quadrisyllabic.
Wiktionary
tetrasyllabic
a. Having four syllables.