noun, plural thymuses, thymi [thahy-mahy] . Anatomy.
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.
Also called thymus gland.

1685–95; < Neo-Latin < Greek thýmos warty excrescence, thymus Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To thymus
World English Dictionary
thymus (ˈθaɪməs)
n , pl -muses, -mi
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
[C17: from New Latin, from Greek thumos sweetbread]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

gland near the base of the neck, 1693, Mod.L., from Gk. thymos "a warty excrescence," used of the gland by Galen, lit. "thyme," probably so called because of a fancied resemblance to a bunch of thyme.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

thymus thy·mus (thī'məs)
n. pl. thy·mus·es

  1. A lymphoid organ that is located in the superior mediastinum and lower part of the neck and is necessary in early life for the normal development of immunological function.

  2. The thymus of a calf or lamb.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
thymus   (thī'məs)  Pronunciation Key 
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
Additional portions of thymus tissue are sometimes developed from the fourth branchial pouches.
Thymus continues to grow until the time of puberty and then begins to atrophy.
Lymphatics have been described in the thyroid gland and in the thymus.
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature