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
Once the bait was sorted, the team chose its test subjects, the microorganisms chosen to play the part of aliens were extremophile bacteria.
—
Ars Technica, 12 Feb. 2025
The gut microbiome is a complex ecosystem of trillions of microorganisms that play a role in digestion, immune function, and mental well-being.
—Lindsay Curtis, Verywell Health, 11 Feb. 2025
The microorganisms that coexist with humans changed, too.
—Dhruv Khullar, The New Yorker, 10 Feb. 2025
But bacterial colonies, biofilms, and consortiums of different microorganisms can perform complicated feats of engineering and behavior together, sometimes rivaling what multicellular life can achieve.
—Veronique Greenwood, WIRED, 9 Feb. 2025
See all Example Sentences for microorganism 
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Ars Technica, 12 Feb. 2025
The gut microbiome is a complex ecosystem of trillions of microorganisms that play a role in digestion, immune function, and mental well-being.
—Lindsay Curtis, Verywell Health, 11 Feb. 2025
The microorganisms that coexist with humans changed, too.
—Dhruv Khullar, The New Yorker, 10 Feb. 2025
But bacterial colonies, biofilms, and consortiums of different microorganisms can perform complicated feats of engineering and behavior together, sometimes rivaling what multicellular life can achieve.
—Veronique Greenwood, WIRED, 9 Feb. 2025
See all Example Sentences for microorganism
Dictionary Entries Near microorganism
Cite this Entry
“Microorganism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/microorganism. Accessed 21 Feb. 2025.
Copy CitationKids 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
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