pineal gland
noun
variants
or less commonly pineal
or pineal body
or pineal organ
: a small, typically cone-shaped structure of the brain that arises from the roof of the third ventricle, is enclosed by the pia mater, and functions primarily as an endocrine gland secreting melatonin
Note: The pineal gland varies in morphological complexity, and in some nonmammalian vertebrates (such as various reptiles) may serve a photoreceptive function.
Love words? Need even more definitions?
Merriam-Webster unabridged
Share