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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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 In the United States, tuberculosis is caused by a germ called Mycobacterium tuberculosis, which primarily affects the lungs and can impact other parts of the body such as the brain, kidneys and spine, according to the Centers for Disease Control and Prevention. Karen Garcia, Los Angeles Times, 3 Feb. 2026 Other findings from the report included confirmation that the biolaboratory had contained thousands of samples of potential pathogens, such as HIV, malaria, tuberculosis, and COVID. Thao Nguyen, USA Today, 3 Feb. 2026 The vast majority of people infected with TB have a latent form of the bacteria, mycobacterium tuberculosis, which remains dormant and non-transmissible — sometimes a hibernating infection can lie dormant for decades. Chase Hunter, Mercury News, 31 Jan. 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

Browse Nearby Words

Cite this Entry

“Tuberculosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tuberculosis. Accessed 11 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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