pineal apparatus: Meaning and Definition of

pin'eal apparat'us

Pronunciation: [key]
  1. a median outgrowth of the roof of the diencephalon in vertebrates that in some develops into the pineal eye and in others into the pineal gland.
  2. See
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.