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

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

Read More: 5 of the World’s Most Intelligent Animals In contrast to other night hunters, like owls, who have a handy tapetum layer to reflect extra light through their retina, tarsiers simply evolved very large eyes. —Max Bennett, Discover Magazine, 23 Feb. 2024

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