The Collaborative International Dictionary
Bacchius
Bacchius \Bac*chi"us\, n.; pl. Bacchii . [L. Bacchius pes, Gr. "o Bakchei^os (sc. poy`s foot).] (Pros.) A metrical foot composed of a short syllable and two long ones; according to some, two long and a short.
Wiktionary
bacchius
n. (context prosody English) A metrical foot composed of a short syllable and two long ones; according to some, two long and a short.