microorganism meaning

[ˌmaɪ.kɹəʊˈɔː.ɡən.ɪ.zəm̩]

[ˌmaɪ.kɹoʊˈɔːɹ.ɡən.ɪ.zəm̩]

WMicroorganism

A microorganism (from the Greek: μικρός, mikros, "small" and ὀργανισμός, organismós, "organism") is a microscopic living organism, which may be single celled or multicellular.
Microorganisms are very diverse and include all the bacteria and archaea and almost all the protozoa. They also include some fungi, algae, and certain animals, such as rotifers. Many macroscopic animals and plants have microscopic juvenile stages.
Microorganisms live in every part of the biosphere, including soil, hot springs, "seven miles deep" in the ocean, "40 miles high" in the atmosphere and inside rocks far down within the Earth's crust (see also endolith).

Definition of microorganism in English Dictionary

NounPLmicroorganismsPREmicro-SUF-ism
1. (microbiology) An organism that is too small to be seen by the unaided eye, especially a single-celled organism, such as a bacterium.
  1. The cud is then reswallowed and further digested by specialized microorganisms that live in the rumen.
More Examples
1. Used in the Middle of Sentence
  - In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere.