Microorganism

/ˌmaɪ.kroʊˈɔːr.ɡən.ɪ.zəm/

Meaning & Definition

noun

A microscopic organism, such as a bacterium, virus, or fungus, that can only be seen with a microscope.

Researchers discovered a new microorganism that thrives in extreme temperatures.

A small living organism, often unicellular, that can exist independently or as part of a larger organism.

The human gut is home to trillions of microorganisms that aid in digestion.

Any organism of microscopic size, especially those that are pathogenic.

Microorganisms are responsible for many infectious diseases in humans.

Coined in the mid-19th century, from 'micro-' meaning small and 'organism' meaning a living entity.

germ theory

The theory that certain diseases are caused by the presence and actions of microorganisms.

microbial life

Life forms that are too small to be seen with the naked eye, primarily microorganisms.

microbial ecology

The study of the relationship between microorganisms and their environment.

bacterium

A single-celled organism that can belong to the domain Bacteria.

virus

A microscopic infectious agent that replicates only inside the living cells of an organism.

fungus

Any member of the group of eukaryotic organisms that includes yeasts, molds, and mushrooms.