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

/ 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 Words From

• mi·cro·or·gan·ic [mahy-kroh-awr-, gan, -ik], micro·organ·ismal adjective

Word History and Origins

Origin of microorganism¹

First recorded in 1875–80; micro- + organism

Example Sentences

Think about a microorganism gathering to build a larger design.

From Washington Post

Gore has discovered rules that allow him to make predictions about simple micro-ecological systems, including the gut microorganisms of laboratory worms and bacterial communities in samples of soil.

From Quanta Magazine

As the months progressed and the sun rose higher, the team found that algal growth accelerated, reaching its peak growth rate for the year in April and May, despite the microorganisms still being covered by ice.

From Science News

There is a reason that biologists call the “biofilm” of microorganisms that cover moist surfaces “bacterial lawns.”

From Nautilus

It would be prudent to consider the arms race between humans and microorganisms as a long-term affair, and not to take our apparent success for granted.

From Quanta Magazine

And the same thing happens when a Venerian is attacked by an Earthly microorganism.

From Project Gutenberg

A microorganism which apparently has a specific relationship to Rocky Mountain spotted fever.

From Project Gutenberg

The disease is caused by a microorganism and several bacteria have been suspected of being responsible.

From Project Gutenberg

Staphylococcus pyogenes aureus—a microorganism producing yellow pus.

From Project Gutenberg

Staphylococcus pyogenes citreus—a microorganism producing lemon-colored pus.

From Project Gutenberg

Related Words

• bacterium
• microbe
• pathogen
• virus