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

Some microorganisms, such as the brain-eating amoeba Naegleria fowleri, can enter the brain this way, but those incidents are rare. —Sarah Kuta, Smithsonian Magazine, 18 Sep. 2024

For microbial leather, microorganisms such as yeast and bacteria undergo a fermentation process that produces byproducts that can be processed into a leather-like material. —Jennifer Bringle, Sourcing Journal, 18 Sep. 2024

But it’s not generally thought that most microorganisms make and survive such long-distance journeys. —Lauren Leffer, Popular Science, 11 Sep. 2024

But this can take away from the microorganisms providing the current nutrients in the soil to your plants. —Lauren David, Southern Living, 3 Sep. 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