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

Keep scrolling for more

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, "Dear Doctor: What to do if I remember getting a certain vaccine but there’s no record of it?," 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, "Pompeo: Iran supreme leader's 'fabrications' about coronavirus put lives at risk," 24 Mar. 2020 Conversely, researchers note drops in other diseases such as pneumococcus and diarrhea after widespread adoption of measles vaccinations. National Geographic, "What's it like moving farther from home?," 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, "Measles vaccines protect against more than just measles. Here's how.," 4 Mar. 2019 The pneumococcus bacteria can cause deadly secondary infections, especially in older people who get the flu or whooping cough. Paul Sisson,, "Which vaccines do home caregivers need?," 24 Apr. 2018 Bacterial meningitis is often caused by pneumococcus, which can be prevented by vaccine. Lynne Terry,, "Gresham mom, 36, gets flu; days later she dies," 24 Jan. 2018 But when our defenses fail us, pneumococcus can migrate, multiply, and set off life-threatening infectious disease. Annabelle Timsit, The Atlantic, "Drugs in Afghanistan and Vaccines in Bangladesh: The Week in Global-Affairs Writing," 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, "How Healthy Is Hillary Clinton? Doctors Weigh In," 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.

See More

First Known Use of pneumococcus

1885, in the meaning defined above

History and Etymology for pneumococcus

New Latin

Keep scrolling for more

Learn More about pneumococcus

Time Traveler for pneumococcus

Time Traveler

The first known use of pneumococcus was in 1885

See more words from the same year

Statistics for pneumococcus

Last Updated

15 May 2021

Cite this Entry

“Pneumococcus.” Dictionary, Merriam-Webster, Accessed 15 May. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

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

Comments on pneumococcus

What made you want to look up pneumococcus? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Words Used by Nabokov Quiz

  • image1676440788
  • Choose the best definition or synonym for the word in bold: "There are some eructations that sound like cheers—at least, mine did." Lolita
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


Anagram puzzles meet word search.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!