microorganism

[mahy-kroh-awr-guh-niz-uhm]

noun

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

microorganism

/ ˌmaɪkrəʊˈɔːɡəˌnɪzəm /

noun

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

microorganism

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

Word History and Origins

Origin of microorganism¹

First recorded in 1875–80; micro- + organism

Example Sentences

"The more I work with more microorganisms, the more I appreciate just how robust E. coli is," he says.

From BBC

To find out what that “something” was, the team turned to a set of techniques that reveals which genes are being expressed by what microorganisms.

From Los Angeles Times

She said lithium mining impacts microorganisms that birds feed on in these waters, so the whole food chain is affected.

From BBC

Plastics, microplastics and toxic chemicals can hurt and kill the microorganisms that make his compost healthy and valued.

From Los Angeles Times

“Mycelium has the advantage that it can be mass-produced under controlled, aseptic conditions, assuring specified levels of key compounds and preventing contamination by undesirable microorganisms and insects,” adds Saxe.

From Los Angeles Times

Related Words

• bacterium 
• microbe 
• pathogen 
• virus