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
Probiotic Foods Probiotics are beneficial microorganisms, including bacteria and yeasts, that help increase good bacteria in the gut while reducing harmful ones.
—
Jamie Johnson, Verywell Health, 22 May 2025
Gut Benefits of Probiotics Your GI tract is full of microorganisms, some good and some bad.
—Health, 19 May 2025
But some microorganisms, known as extremophiles, show impressive resilience in inhospitable environments, whether that's the vacuum of space, hydrothermal vents on the slopes of undersea volcanoes, or even NASA clean rooms.
—Stefanie Waldek, Space.com, 18 May 2025
Yet, even after the French microbiologist Louis Pasteur patented the technology of pasteurization, or heating liquids to kill microorganisms, in 1865, Americans largely continued to consume raw milk for several more decades.
— Made By History, Time, 29 Apr. 2025
See All Example Sentences for microorganism
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Jamie Johnson, Verywell Health, 22 May 2025
Gut Benefits of Probiotics Your GI tract is full of microorganisms, some good and some bad.
—Health, 19 May 2025
But some microorganisms, known as extremophiles, show impressive resilience in inhospitable environments, whether that's the vacuum of space, hydrothermal vents on the slopes of undersea volcanoes, or even NASA clean rooms.
—Stefanie Waldek, Space.com, 18 May 2025
Yet, even after the French microbiologist Louis Pasteur patented the technology of pasteurization, or heating liquids to kill microorganisms, in 1865, Americans largely continued to consume raw milk for several more decades.
— Made By History, Time, 29 Apr. 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 6 Jun. 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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