epibatus

from The Century Dictionary.

• In ancient prosody, marked by special beating of time (as with the foot): a distinctive epithet of a pæonic foot of doubled or decasemic magnitude, in contradistinction to the pæon diagyios (see diagyios), or ordinary pæonic foot of pentasemic magnitude, commonly called the cretic.
• noun The decasemic pæon (pæon epibatus). See I.