tapetum

noun

ta·​pe·​tum tə-ˈpē-təm 

plural tapeta tə-ˈpē-tə 

1

: any of various reflective membranous layers or areas especially of the choroid and retina of the eye

2

: a layer of nutritive cells that invests the sporogenous tissue in the sporangium of vascular plants

Examples of tapetum in a Sentence

Recent Examples on the Web

Deer eyes also possess a tapetum lucidum, a reflective layer behind the retina. — Encyclopedia Britannica, 2 Sep. 2026

If a small amount of light goes in, from a streetlamp, headlights, or even the moon, the tapetum gives the eye another chance to catch it, making things appear brighter and the eyes appear to glow. — Alice Gibbs, MSNBC Newsweek, 21 Aug. 2025

The sharks also retain a tapetum lucidum, a reflective layer behind the retina that boosts their ability to capture light. — Melissa Cristina Márquez, Forbes.com, 14 May 2025

With the tapetum lucidum and many rods, cats are extraordinarily sensitive to any amount of light. — Katie Liu, Discover Magazine, 26 Oct. 2023

Exactly how the tapetum’s fibers close in on one another isn’t yet clear, even two decades in. — Katherine J. Wu, The Atlantic, 28 June 2022

The part of the eye that changes color is the tapetum lucidum, a layer of tissue found behind the retina. — Nayeli Lomeli, USA TODAY, 15 Dec. 2021

Word History

Etymology

New Latin, from Latin tapete carpet, tapestry, from Greek tapēt-, tapēs carpet

First Known Use

1713, in the meaning defined at sense 1

Medical Definition

tapetum

noun

ta·​pe·​tum tə-ˈpēt-əm 

plural tapeta -ˈpēt-ə 

1

: any of various membranous layers or areas especially of the choroid and retina of the eye

specifically : tapetum lucidum

2

: a layer of nerve fibers derived from the corpus callosum and forming part of the roof of each lateral ventricle of the brain