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.

---

microorganism British  

/ ˌmaɪkrəʊˈɔːɡəˌnɪzəm /

noun

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

---

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

---

Other Word Forms

• microorganic adjective
• microorganismal adjective

Etymology

Origin of microorganism

First recorded in 1875–80; micro- + organism

Example Sentences

"We know that the microorganisms that produce oxygen were around well before the Great Oxidation Event," Husain says.

From Science Daily

Yet this everyday microorganism may also offer insight into a far bigger question: how life might endure the extreme conditions found beyond Earth.

From Science Daily

This enormous and constantly changing community of microorganisms is shaped by countless chemical exchanges, both among the microbes themselves and between microbes and the human body.

From Science Daily

"This work highlights a new way environmental change can affect marine ecosystems, not simply by limiting resources, but by disrupting the internal physiology of dominant microorganisms," Cheng said.

From Science Daily

Some trials show that the sweeteners can raise blood sugar, weaken blood-sugar control and cause dysfunction in the gut microbiome, the collection of bacteria and other microorganisms in the gut.

From The Wall Street Journal

Related Words

• bacterium
• microbe
• pathogen
• virus