microorganism

American  

[mahy-kroh-awr-guh-niz-uhm] / ˌmaɪ kroʊˈɔr gəˌnɪz əm /

noun

1. any organism too small to be viewed by the unaided eye, as bacteria, protozoa, and some fungi and algae.

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microorganism British  

/ ˌmaɪkrəʊˈɔːɡəˌnɪzəm /

noun

1. any organism, such as a bacterium, protozoan, or virus, of microscopic size

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microorganism Scientific  

/ mī′krō-ôr′gə-nĭz′əm /

1. An organism that can be seen only with the aid of a microscope and that typically consists of only a single cell. Microorganisms include bacteria, protozoans, and certain algae and fungi.

2. See Note at germ

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Other Word Forms

• microorganic adjective
• microorganismal adjective

Etymology

Origin of microorganism

First recorded in 1875–80; micro- + organism

Example Sentences

The gut microbiome consists of trillions of microorganisms living in the digestive tract, where they play important roles in digestion and overall health.

From Science Daily

To identify which bacteria and microbial byproducts contribute to these metabolite patterns, the researchers treated obesity and diabetes susceptible mice with an antibiotic designed to target specific intestinal microorganisms.

From Science Daily

Plants rely on cell-surface receptors to sense chemical signals from microorganisms in the soil.

From Science Daily

“These microorganisms live with you for the rest of your life and they’re resetting your genes,” she says.

From The Wall Street Journal

In this study, the researchers measured the nitrogen isotopic composition in corals to infer how much nitrogen microorganisms have fixed over the past 120 years.

From Science Daily

Related Words

• bacterium
• microbe
• pathogen
• virus