Anaerobe Definition

ănə-rōb, ăn-ârōb
noun
A microorganism that can live and grow where there is no free oxygen: it may not be able to grow if any oxygen is present.
Webster's New World
An organism, such as a bacterium, that can live in the absence of free oxygen.
American Heritage Medicine

An anaerobic organism; one that does not require oxygen to sustain its metabolic processes.

Wiktionary