ta·​pe·​tum tə-ˈpē-təm How to pronounce tapetum (audio)
plural tapeta tə-ˈpē-tə How to pronounce tapetum (audio)
: any of various reflective membranous layers or areas especially of the choroid and retina of the eye
: 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 Humans lack a tapetum, but many of us have seen one of its tricks: The tapetum is what makes cat, dog, and raccoon eyes glow in nighttime photographs. Katherine J. Wu, The Atlantic, 28 June 2022 Instead of a tapetum, Reynolds suggests the boy may just have an especially high number of rods, our photoreceptors that work well in low light. Sarah Zhang, Discover Magazine, 2 Feb. 2012 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 The tapetum lucidum, which lines most of the back of the retina, comes into play in low-light situations, allowing the cat's eye to take in extra light. Star Tribune, 21 May 2021 Some creatures, including cats, raccoons, and dogs, have a layer of reflective tissue in their eyes known as the tapetum lucidum. Matt Simon, WIRED, 14 Jan. 2015 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tapetum.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

First Known Use

1713, in the meaning defined at sense 1

Time Traveler
The first known use of tapetum was in 1713

Dictionary Entries Near tapetum

Cite this Entry

“Tapetum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tapetum. Accessed 29 Sep. 2023.

Medical Definition


ta·​pe·​tum tə-ˈpēt-əm How to pronounce tapetum (audio)
plural tapeta -ˈpēt-ə How to pronounce tapetum (audio)
: any of various membranous layers or areas especially of the choroid and retina of the eye
specifically : tapetum lucidum
: a layer of nerve fibers derived from the corpus callosum and forming part of the roof of each lateral ventricle of the brain

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