thymus

noun

thy·​mus ˈthī-məs How to pronounce thymus (audio)
variants or thymus gland
plural thymuses also thymi ˈthī-ˌmī How to pronounce thymus (audio)
: a glandular structure of largely lymphoid tissue that functions especially in cell-mediated immunity by being the site where T cells develop, is present in the young of most vertebrates typically in the upper anterior chest or at the base of the neck, and gradually decreases in size and activity after puberty

Examples of thymus in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The thymus, which produces infection-fighting T cells, reaches its peak size at puberty and then steadily shrinks. Lisa M. Krieger, The Mercury News, 29 Oct. 2024 Adding the pig's thymus, Montgomery said, should protect the pig kidney from being attacked by the human immune system. Karen Weintraub, USA TODAY, 24 Apr. 2024 Along with its kidney, the NYU pig, bred by United Therapeutics, also provided its thymus, an organ of the immune system. Karen Weintraub, USA TODAY, 24 Apr. 2024 Scientists have grown mice containing cells from rat pancreases or thymuses, as well as rats that have pancreas or kidney cells from mice. Will Sullivan, Smithsonian Magazine, 2 May 2024 See all Example Sentences for thymus 

Word History

Etymology

New Latin, from Greek thymos warty excrescence, thymus

First Known Use

1578, in the meaning defined above

Time Traveler
The first known use of thymus was in 1578

Dictionary Entries Near thymus

Cite this Entry

“Thymus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thymus. Accessed 28 Nov. 2024.

Kids Definition

thymus

noun
thy·​mus ˈthī-məs How to pronounce thymus (audio)
plural thymuses also thymi -ˌmī How to pronounce thymus (audio)
: a gland that is found in the young of most vertebrates usually in the chest near the heart, that before and for a time after birth has very important effects on the production and development of T cells, and that becomes less active and gradually shrinks or disappears with age

Medical Definition

thymus

noun
thy·​mus ˈthī-məs How to pronounce thymus (audio)
variants or thymus gland
plural thymuses also thymi -ˌmī How to pronounce thymus (audio)
: a glandular structure of largely lymphoid tissue that functions in cell-mediated immunity by being the site where T cells develop, that is present in the young of most vertebrates typically in the upper anterior chest or at the base of the neck, that arises from the epithelium of one or more embryonic branchial clefts, and that gradually decreases in size and activity after puberty

More from Merriam-Webster on thymus

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