pneu·​mo·​coc·​cus | \ ˌnü-mə-ˈkä-kəs How to pronounce pneumococcus (audio) , ˌnyü- \
plural pneumococci\ ˌnü-​mə-​ˈkäk-​ˌsī How to pronounce pneumococcus (audio) , -​ˌsē ; -​ˈkä-​ˌkī , -​ˌkē , ˌnyü-​ \

Definition of pneumococcus

: a bacterium (Streptococcus pneumoniae) that causes an acute pneumonia involving one or more lobes of the lung

Other Words from pneumococcus

pneumococcal \ ˌnü-​mə-​ˈkä-​kəl How to pronounce pneumococcus (audio) , ˌnyü-​ \ adjective

Examples of pneumococcus in a Sentence

Recent Examples on the Web These protect against pneumonia and other serious diseases, such as meningitis and bacteremia, from the bacteria Streptococcus pneumoniae, also called pneumococcus. Dr. Keith Roach, oregonlive, 10 May 2021 Last week, Merkel received a vaccine shot against pneumococcus, a pneumonia-causing bacteria, from a doctor who later tested positive for coronavirus, her office said Sunday. NBC News, 24 Mar. 2020 Conversely, researchers note drops in other diseases such as pneumococcus and diarrhea after widespread adoption of measles vaccinations. National Geographic, 6 Nov. 2019 However, the data show that’s not the case: Not only did cases of measles plummet once vaccine use became widespread, but cases of other diseases dropped as well—pneumococcus, diarrhea, and more. National Geographic, 4 Mar. 2019 The pneumococcus bacteria can cause deadly secondary infections, especially in older people who get the flu or whooping cough. Paul Sisson,, 24 Apr. 2018 Bacterial meningitis is often caused by pneumococcus, which can be prevented by vaccine. Lynne Terry,, 24 Jan. 2018 But when our defenses fail us, pneumococcus can migrate, multiply, and set off life-threatening infectious disease. Annabelle Timsit, The Atlantic, 27 Oct. 2017 Mrs. Clinton’s pneumonia affects her right lung’s middle lobe, according to Dr. Bardack, a location that suggests that it was caused by bacteria, commonly pneumococcus. Lawrence K. Altman, M.d., New York Times, 18 Sep. 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'pneumococcus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of pneumococcus

1885, in the meaning defined above

History and Etymology for pneumococcus

New Latin

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Time Traveler for pneumococcus

Time Traveler

The first known use of pneumococcus was in 1885

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Cite this Entry

“Pneumococcus.” Dictionary, Merriam-Webster, Accessed 4 Dec. 2021.

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More Definitions for pneumococcus


pneu·​mo·​coc·​cus | \ ˌn(y)ü-mə-ˈkäk-əs How to pronounce pneumococcus (audio) \
plural pneumococci\ -​ˈkäk-​ˌ(s)ī How to pronounce pneumococcus (audio) \

Medical Definition of pneumococcus

: a bacterium of the genus Streptococcus (S. pneumoniae) that causes an acute pneumonia involving one or more lobes of the lung

More from Merriam-Webster on pneumococcus Encyclopedia article about pneumococcus


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