microorganism

noun

mi·​cro·​or·​gan·​ism ˌmī-krō-ˈȯr-gə-ˌni-zəm 

: an organism (such as a bacterium or protozoan) of microscopic or ultramicroscopic size

Examples of microorganism in a Sentence

Recent Examples on the Web

These experiments resulted in the creation of certain bioactive compounds that were subsequently fed to mice to determine their effect on the microbiome—a collection of microorganisms—of the rodents' intestines. —Newsweek, 21 Dec. 2024

The microbiome is the community of microorganisms, including bacteria, viruses, fungi, archaea and other microbes, that live on or inside the body. —Grrlscientist, Forbes, 16 Dec. 2024

Gut Microbiota Imbalance The gut microbiome is a community of trillions of microorganisms, including bacteria, viruses, and fungi, that live in the gastrointestinal tract. —Lindsay Curtis, Health, 15 Dec. 2024

Historically, water systems used chlorine, a chemical element, as a disinfectant for drinking water to remove harmful bacteria, viruses and certain microorganisms. —Mary Kekatos, ABC News, 22 Nov. 2024

Word History

Etymology

International Scientific Vocabulary

First Known Use

1880, in the meaning defined above

Kids Definition

microorganism

noun

mi·​cro·​or·​gan·​ism ˌmī-krō-ˈȯr-gə-ˌniz-əm 

: an organism (as a bacterium) of microscopic or less than microscopic size

Medical Definition

microorganism

noun

mi·​cro·​or·​gan·​ism -ˈȯr-gə-ˌniz-əm 

: an organism of microscopic or ultramicroscopic size