Me*tapter*yg"i*al

from The Collaborative International Dictionary of English v.0.48

Metapterygium \Me*tap`te*ryg"i*um\, n. [NL., fr. Gr. ? after + ?
   fin.] (Anat.)
   The posterior of the three principal basal cartilages in the
   fins of fishes. -- {Me*tap`ter*yg"i*al}, a.
   [1913 Webster]