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
Bleach and borax are toxic to plants and microorganisms.
—
Erica Browne Grivas, Better Homes & Gardens, 16 July 2025
The study showed that COPD patients’ alveolar macrophages — a type of lung cell that removes dust, particles and microorganisms from the lungs — contain more carbon than those of smokers.
—The Washington Post, San Diego Union-Tribune, 8 July 2025
Collecting samples of surface material for analysis from the Destiny laboratory and the Quest airlock to see whether microorganisms might exist on the exterior of the orbital complex.
—Andy Humbles, The Tennessean, 2 July 2025
Its many layers protect our body from external threats like UV radiation, chemicals, and microorganisms.
—Jenny Lehmann, Discover Magazine, 30 June 2025
See All Example Sentences for microorganism
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Erica Browne Grivas, Better Homes & Gardens, 16 July 2025
The study showed that COPD patients’ alveolar macrophages — a type of lung cell that removes dust, particles and microorganisms from the lungs — contain more carbon than those of smokers.
—The Washington Post, San Diego Union-Tribune, 8 July 2025
Collecting samples of surface material for analysis from the Destiny laboratory and the Quest airlock to see whether microorganisms might exist on the exterior of the orbital complex.
—Andy Humbles, The Tennessean, 2 July 2025
Its many layers protect our body from external threats like UV radiation, chemicals, and microorganisms.
—Jenny Lehmann, Discover Magazine, 30 June 2025
See All Example Sentences for microorganism
Cite this Entry
“Microorganism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/microorganism. Accessed 29 Jul. 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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