tuberculosis

noun

tu·​ber·​cu·​lo·​sis tu̇-ˌbər-kyə-ˈlō-səs How to pronounce tuberculosis (audio)
tyu̇-
plural tuberculoses tu̇-ˌbər-kyə-ˈlō-ˌsēz How to pronounce tuberculosis (audio)
tyu̇-
: a highly variable communicable disease of humans and some other vertebrates that is caused by the tubercle bacillus and rarely in the U.S. by a related mycobacterium (Mycobacterium bovis), that affects especially the lungs but may spread to other areas (such as the kidney or spinal column), and that is characterized by fever, cough, difficulty in breathing, formation of tubercles, caseation, pleural effusions, and fibrosis

Examples of tuberculosis in a Sentence

Recent Examples on the Web
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Malaria was rampant in the South, and fever diseases, tuberculosis, syphilis, and polio killed tens of thousands of Americans annually. Vann R. Newkirk Ii, The Atlantic, 9 Feb. 2026 While highly contagious, not everyone who comes into contact with tuberculosis gets sick; the disease can be fatal if not properly treated. David Matthews, New York Daily News, 6 Feb. 2026 About tuberculosis Tuberculosis can be deadly if not treated properly. Mark Prussin, CBS News, 5 Feb. 2026 Even a mild case of measles can lead to lingering damage to the immune system known as immune amnesia, making a person more vulnerable to other diseases ranging from flu to tuberculosis. Tom Gavin, EverydayHealth.com, 3 Feb. 2026 See All Example Sentences for tuberculosis

Word History

Etymology

New Latin

First Known Use

1839, in the meaning defined above

Time Traveler
The first known use of tuberculosis was in 1839

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Cite this Entry

“Tuberculosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tuberculosis. Accessed 13 Feb. 2026.

Kids Definition

tuberculosis

noun
tu·​ber·​cu·​lo·​sis t(y)u̇-ˌbər-kyə-ˈlō-səs How to pronounce tuberculosis (audio)
: a disease of human beings and some other vertebrates caused by a bacterium and usually marked by wasting, fever, and formation of cheesy tubercles that in human beings occur mostly in the lungs
tuberculous
t(y)u̇-ˈbər-kyə-ləs
adjective

Medical Definition

tuberculosis

noun
tu·​ber·​cu·​lo·​sis t(y)u̇-ˌbər-kyə-ˈlō-səs How to pronounce tuberculosis (audio)
plural tuberculoses -ˌsēz How to pronounce tuberculosis (audio)
: a usually chronic highly variable disease that is caused by a bacterium of the genus Mycobacterium (M. tuberculosis) and rarely in the United States by a related mycobacterium (M. bovis), is usually communicated by inhalation of the airborne causative agent, affects especially the lungs but may spread to other areas (as the kidney or spinal column) from local lesions or by way of the lymph or blood vessels, and is characterized by fever, cough, difficulty in breathing, inflammatory infiltrations, formation of tubercles, caseation, pleural effusion, and fibrosis

called also TB

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