parietal eye

noun

1

: pineal gland

—used especially for a pineal gland that possesses a photoreceptive function

called also pineal eye

2

: a photoreceptive structure of some nonmammalian vertebrates (such as lizards) especially when eyelike in composition with a distinguishable lens and retina

called also pineal eye

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now