microorganism

[ mahy-kroh-awr-guh-niz-uh m ]
/ ˌmaɪ kroʊˈɔr gəˌnɪz əm /
SEE SYNONYMS FOR microorganism ON THESAURUS.COM

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

OTHER WORDS FROM microorganism

mi·cro·or·gan·ic [mahy-kroh-awr-gan-ik] /ˌmaɪ kroʊ ɔrˈgæn ɪk/, mi·cro·or·gan·is·mal, adjective

Words nearby microorganism

micronodular, micronucleate, micronucleus, micronutrient, micronychia, microorganism, microorganisms, micropalaeontology, micropaleontology, microparasite, micropathology

Words related to micro-organism

microorganism, germ, virus, bug, bacterium, bacillus, pathogen, microbe, parasite, illness, ailment, sickness, disease, infection, egg, unit, plague, antibody, crud, embryo

Example sentences from the Web for micro-organism

British Dictionary definitions for micro-organism

microorganism
/ (ˌmaɪkrəʊˈɔːɡəˌnɪzəm) /

noun

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

Medical definitions for micro-organism

microorganism
[ mī′krō-ôr′gə-nĭz′əm ]

n.

An organism of microscopic or submicroscopic size, especially a bacterium or protozoan.

Scientific definitions for micro-organism

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.