microorganism

[mahy-kroh-awr-guh-niz-uh m] /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.
Origin
1875-80; micro- + organism
Related forms
microorganic
[mahy-kroh-awr-gan-ik] /ˌmaɪ kroʊ ɔrˈgæn ɪk/ (Show IPA), microorganismal, adjective
Examples from the web for microorganisms
  • The bubbling torrent is full of fecal microorganisms responsible for typhoid, cholera and amoebic dysentery.
  • The hot bath kills harmful microorganisms, seals the jars and makes them airtight.
  • Don't be surprised if your kids are clamoring for microorganisms this holiday season.
  • He knew that microorganisms could live in oxygen-deprived environments by processing things such as sulfate and methane.
  • For decomposition to take place, microorganisms must be present to break down the materials.
  • Biodegradation occurs when bacteria or other microorganisms break down oil as part of their life cycle.
  • Composting requires microorganisms that thrive in damp, oxygen-rich conditions.
  • Nutrients from the hippos' dung provide food for microorganisms, which in turn are food for fish.
  • Their underbellies take on a yellowish hue from the millions of microorganisms that take up residence in their skin.
  • Of great interest to the scientists this year is the complex life of the microorganisms living at the hydrothermal vent sites.
British Dictionary definitions for microorganisms

microorganism

/ˌmaɪkrəʊˈɔːɡəˌnɪzəm/
noun
1.
any organism, such as a bacterium, protozoan, or virus, of microscopic size
microorganisms in Medicine

microorganism mi·cro·or·gan·ism (mī'krō-ôr'gə-nĭz'əm)
n.
An organism of microscopic or submicroscopic size, especially a bacterium or protozoan.

microorganisms in Science
microorganism
  (mī'krō-ôr'gə-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.
microorganisms in Culture

microorganisms definition


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