Source : Webster's Revised Unabridged Dictionary (1913)

Basipterygium \Ba*sip`te*ryg"i*um\, n. [NL., fr. Gr. ? a base +
   ? a fin.] (Anat.)
   A bar of cartilage at the base of the embryonic fins of some
   fishes. It develops into the metapterygium. --
   {Ba*sip`ter*yg"i*al}, a.