bacteria

/bækˈtɪəɹ.ɪ.ə/noun

Very small living things, each made of a single cell, found almost everywhere; some cause disease and others are helpful.

Example sentences

“Washing your hands removes bacteria that can make you sick.”
“Certain bacteria in yogurt aid digestion.”
“Bacteria grow quickly in food left out in the heat.”

Grammatically plural: bacteria are, with 'bacterium' as the singular. Don't confuse bacteria with viruses, which antibiotics cannot kill.

Often confused with bacteria

bacteria vs virus: virus (noun): A tiny germ, much smaller than bacteria, that gets into living cells and causes diseases such as colds and flu.

Related words

germA tiny living thing, such as a bacterium or virus, that can cause illness.diseaseA condition that makes a person, animal, or plant unwell or stops it working properly, unlike an injury, which usually happens in an instant.outbreakThe sudden start or rapid spread of something unpleasant, such as a disease.chronicLasting for a long time or coming back again and again, used of problems or illnesses.pandemicA disease that spreads across many countries and infects a very large share of the population.acuteVery strong, keen, or sharp in effect or perception.