thymus

noun thy·mus \ ˈthī-məs \
variants: or thymus gland

Definition of thymus

plural thymuses also thymi play \-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

Recent Examples of thymus from the Web

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


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

Learn More about thymus


Seen and Heard

What made you want to look up thymus? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

serious difficulty or misfortune

Get Word of the Day daily email!

Test Your Vocabulary

The Exceptions Quiz III

  • one-green-toy-robot-amidst-many-red-toy-robots
  • Which of these words does not mean "nonsense"?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!