thymus

noun thy·mus \ ˈthī-məs \

variants: or thymus gland

|Updated on: 21 Jun 2018

Definition of thymus

plural thymuses also thymi play \ˈthī-ˌmī\

: 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

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Recent Examples of thymus from the Web

Dria has been waiting over a year for a thymus transplant to regenerate her immune cells.

— julie gallant, Ramona Sentinel, "Family stays by side of 4-year-old awaiting transplants," 12 June 2018
Even more critical is his need for a thymus transplant.

— peter rowe, sandiegouniontribune.com, "A Mother's Day gift for a struggling baby: loving attention," 13 May 2018
In the older sedentary people, the output of new T cells from the thymus glands was low.

— gretchen reynolds, New York Times, "How Exercise Can Keep Aging Muscles and Immune Systems ‘Young’," 14 Mar. 2018
The cause was complications from a rare cancer of the thymus, said his wife Christina Llewellyn.

— ellie silverman, Washington Post, "Ed Bordley, championship-winning blind wrestler and Harvard Law graduate, dies at 61," 2 Mar. 2018
Other parts of the immune system include the thymus, spleen, lymph nodes, lymphocytes, white blood cells, and antibodies.

— Philly.com, "Teens and their tonsils: When do they need to be out?," 1 Mar. 2018
Yes, sweetbreads are organ meats, but fear not: These thymus and pancreas glands are notably mild and smooth.

— alison cook, Houston Chronicle, "Eat this: Mesquite-grilled sweetbreads at El Tiempo Cantina," 1 Nov. 2017
Meanwhile, his mother, Kim, was fighting a rare cancer affecting her thymus, an organ of the immune system.

— david woods, Indianapolis Star, "Butler basketball looks for Sean McDermott to fill void," 4 Oct. 2017
GHRH is normally produced in the brain, but Hanley was essentially turning a pencil-eraser-size part of his thigh into a gland that made the molecule, which stimulates the heart, the kidneys, and the thymus.

— tad friend, The New Yorker, "Silicon Valley’s Quest to Live Forever," 24 Mar. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thymus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of thymus

New Latin, from Greek thymos warty excrescence, thymus

NEW! Time Traveler

First Known Use: 1578

in the meaning defined above

See Words from the same year

Medical Dictionary

thymus

noun thy·mus \ ˈthī-məs \

variants: or thymus gland

medical Definition of thymus

plural thymuses also thymi play \-ˌmī\

: 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