microorganism; microbe; germ
General scientific and everyday term for microscopic organisms, including bacteria, viruses, and fungi. Neutral register.
Microorganisms are so small they cannot be seen with the naked eye.
This yogurt contains live microorganisms.
Microorganisms tend to multiply easily in damp places.
We cultured the microorganism in the lab.
Microorganisms decompose dead leaves and turn them into soil.
Many microorganisms also live in the deep sea.
biodegradation; microbial decomposition
microbiologist