microorganism

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

noun

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

Origin of microorganism

First recorded in 1875–80; micro- + organism

Related forms

mi·cro·or·gan·ic [mahy-kroh-awr-gan-ik] /ˌmaɪ kroʊ ɔrˈgæn ɪk/, mi·cro·or·gan·is·mal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for microorganisms

British Dictionary definitions for microorganisms

microorganism

/ (ˌmaɪkrəʊˈɔːɡəˌnɪzəm) /

noun

any organism, such as a bacterium, protozoan, or virus, of microscopic size
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for microorganisms

microorganism

[ mī′krō-ôrgə-nĭz′əm ]

n.

An organism of microscopic or submicroscopic size, especially a bacterium or protozoan.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for microorganisms

microorganism

[ mī′krō-ôrgə-nĭz′əm ]

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. See Note at germ.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for microorganisms

microorganisms


Organisms so small that they can be seen only through a microscope. (See bacteria, protozoa, and viruses.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.