Definition of "microorganism" [mi•cro•ör•gan•ism]

• An organism of microscopic or submicroscopic size, especially a bacterium or protozoan. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""This study gives a systems biology view of how a phenotype, or a 'network state' advantageous to a microorganism is comprised of a tiny subset of a much larger universe of possibilities as provided for in the genome," said Palsson."
• "The single cell of a microorganism is a perfect protein factory."
• ""It exchanges a functional definition of a pathogen -- that is, a microorganism that can do harm -- for a very complicated approach that says: 'Maybe it's a pathogen and maybe it's not, and there are infinite numbers of possibilities'.""