Definition of microorganism
: an organism (such as a bacterium or protozoan) of microscopic or ultramicroscopic size
Recent Examples of microorganism from the Web
Indeed, the popularity of probiotics has grown so much in recent years that manufacturers have even added the microorganisms to cosmetics and mattresses.
According to a 2015 study in the International Journal of Environmental Research and Public Health, more microorganisms exist in the transport vehicles than in the water’s original source, thus transferring the organisms from truck to plane.
The information will be used to develop a giant genetic map, or microbiome, that details the community of microorganisms that live on the surfaces of transportation hubs.
Her findings strikingly shine a light on a handful of microorganisms that apparently separate the guts of elite athletes from average people.
The composting process employs billions of microorganisms to break down organics into the essential component of soil called humus.
The water bureau could either build an ultraviolet treatment plant, projected in bureau planning documents to cost at least $89 million, or a $300 million filtration treatment system that would filter out sediment in addition to microorganisms.
The compound, which is used against a large number of microorganisms in other products, binds chlorine with the gauze in an alcohol solution.
But scientists don’t yet understand how the microorganisms living in our gastrointestinal tract give rise to or affect these conditions, let alone how to fix an unhealthy gut.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'microorganism'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of microorganism
International Scientific Vocabulary
First Known Use: 1880See Words from the same year
MICROORGANISM Defined for English Language Learners
Definition of microorganism for English Language Learners
biology : an extremely small living thing that can only be seen with a microscope
MICROORGANISM Defined for Kids
Definition of microorganism for Students
: a living thing (as a bacterium) that can only be seen with a microscope
Medical Definition of microorganism
: an organism of microscopic or ultramicroscopic size
Seen and Heard
What made you want to look up microorganism? Please tell us where you read or heard it (including the quote, if possible).