The Collaborative International Dictionary
Quadrisyllable
Quadrisyllable \Quad`ri*syl"la*ble\, n. [Quadri- + syllable: cf.
F. quadrisyllabe.]
A word consisting of four syllables.
--De Quincey.
Wiktionary
quadrisyllable
n. A word of four syllables.
Usage examples of "quadrisyllable".
In the second half verse, I do not remember a single instance of deviation from this, though sometimes, but very seldom, the first half verse ends with another quadrisyllable foot.