from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A small glandular organ that is situated behind the top of the breastbone, consisting mainly of lymphatic tissue and serving as the site of T cell differentiation. The thymus increases gradually in size and activity until puberty, after which it begins to atrophy.

from The Century Dictionary.

  • noun A genus of labiate plants, belonging to the tribe Satureineæ and subtribe Menthoideæ; the thyme.
  • noun In anatomy, a fetal structure, vestigial in the adult, one of the so-called ductless glands, of no known function, situated inside the thorax, behind the breast-bone, near the root of the neck.
  • noun In pathology, same as acrothymion.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective (Anat.) Of, pertaining to, or designating, the thymus gland.
  • adjective a ductless gland in the throat, or in the neighboring region, of nearly all vertebrates. In man and other mammals it is the throat, or neck, sweetbread, which lies in the upper part of the thorax and lower part of the throat. It is largest in fetal and early life, and disappears or becomes rudimentary in the adult. The thymus gland functions as the site of maturation of T-lymphocytes (T-cells), which confer cell-mediated immunity on the host organism; thus, removal or malfunciton of the thymus can lead to absence of cell-mediated immunity, and a consequent loss of resistance to infection.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun anatomy, immunology A ductless gland, consisting mainly of lymphatic tissue, located behind the top of the breastbone. It is most active during puberty, after which it shrinks in size. It plays an important role in the development of the immune system and produces lymphocytes.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun large genus of Old World mints: thyme
  • noun a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity; atrophies with age


from The American Heritage® Dictionary of the English Language, 4th Edition

[New Latin, from Greek thumos, warty excrescence, thymus.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From the Modern Latin thymus, from the Ancient Greek θύμος (thumos, "warty excrescence”, (also, as used by Galen) “thymus gland").


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  • Occasionally in the past there were speculations as to the effect on adolescence, and the changes that took place at this time, of the thymus gland (from a Greek word of uncertain derivation).

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  • There is one other thing that we want to do that is also required for rejuvenating the immune system, and that is to restore the size of a very important organ in the immune system called the thymus, which is - for whatever reason - something that shrinks throughout life and gets, even by the sort of age I am, down to 10 or

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  • The tumour, which had started in an organ called the thymus gland in the chest cavity, was also crushing his heart and lungs and constricting the vital arteries supplying his body with blood.

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  • I forgot about the sweetbreads dish, aka thymus gland, here served with eggplant dumplings and ricotta salata.

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  • I forgot about the sweetbreads dish, aka thymus gland, here served with eggplant dumplings and ricotta salata.

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  • The thymus is a tiny organ located near our breastbone that is present in all mammals.

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  • Now off in another part of the body, in a strange little organ called the thymus, T cells are going to school.

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  • Not long ago, I had this sort of mixed reaction when I read that the country musician Naomi Judd, who may have contracted hepatitis C while working as a nurse more than ten years ago, has had some success with a compound called thymus extract.


  • Indeed, they are not of any use at all, except that the first becomes the Eustachian tube bringing the ear-passage into connection with the back of the mouth, and that the second and third have to do with the development of a curious organ called the thymus gland.

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  • The last anatomical point which may give trouble in normal necks is the thymus, which is present in children below the age of two, and covers the lower end of the trachea just above the level of the sternum.

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