microorganism
mic·roor·ga·nism
noun
1.
any organism of microscopic size
Origin
From micro- + organism.
Related words
Broader terms
Part of
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.