thymus

American  

[thahy-muhs] / ˈθaɪ məs /

noun

Anatomy.

• thymuses,
  plural
• thymi
  plural

1. a ductless, butterfly-shaped gland lying at the base of the neck, formed mostly of lymphatic tissue and aiding in the production of T cells of the immune system: after puberty, the lymphatic tissue gradually degenerates.

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thymus British  

/ ˈθaɪməs /

noun

1. a glandular organ of vertebrates, consisting in man of two lobes situated below the thyroid. In early life it produces lymphocytes and is thought to influence certain immunological responses. It atrophies with age and is almost nonexistent in the adult

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thymus Scientific  

/ thī′məs /

1. An organ of the lymphatic system located behind the upper sternum (breastbone). T cells (T lymphocytes) develop and mature in the thymus before entering the circulation. In humans, the thymus stops growing in early childhood and gradually shrinks in size through adulthood, resulting in a gradual decline in immune system function.

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Other Word Forms

Noun Inflected Forms

• thymi
  plural
• thymuses
  plural

Etymology

Origin of thymus

1685–95; < New Latin < Greek thýmos warty excrescence, thymus

Example Sentences

See Examples For:

thymus thymuses

Although lifestyle factors were associated with thymic health, the studies did not investigate whether changing those factors can directly improve thymus function.

From Science Daily ● Jun. 1, 2026

Researchers at Mass General Brigham have uncovered evidence that the thymus, a small immune system organ long thought to lose its importance after childhood, may play a major role in adult health.

From Science Daily ● Jun. 1, 2026

One ongoing study is examining whether unintended radiation exposure to the thymus during lung cancer treatment could affect patient outcomes.

From Science Daily ● Jun. 1, 2026

As a result, the thymus has received relatively little attention in large population studies.

From Science Daily ● Jun. 1, 2026

As pointed out by Ellen J. Patterson the size of the thymus gland should be studied before an esophagoscopy is done on a child.

From Bronchoscopy and Esophagoscopy A Manual of Peroral Endoscopy and Laryngeal Surgery by Chevalier Jackson

Two new studies found that adults with healthier thymuses were more likely to live longer and less likely to develop serious diseases.

From Science Daily ● Jun. 1, 2026

The results showed that patients with healthier thymuses tended to respond better to treatment.

From Science Daily ● Jun. 1, 2026

To cross-check his findings, Dr. Miller took some newborn mice, removed their thymuses, and a week later grafted in new thymuses from mice of a different strain.

From Time Magazine Archive

From some newborn mice he cut out the pinhead-size thymuses.

From Time Magazine Archive