bacteria

noun

Saybak-TEER-ee-uh/bækˈtɪɹ.i.ə/UK/bakˈtɪə̯.ri.ə/

Pluralbacterias, bacteriae

5 meanings of bacteria

1
noun
Plural of bacterium. Use this form when you mean more than one.
Bacteria live in the soil, in water, and even inside our bodies.
Some bacteria help us digest the food we eat.
Note
2
nounUScountable
A single kind, type, or strain of microbe.
Like one type of ant out of all the different kinds of ant.
Scientists discovered a new bacteria living deep in the ocean.
This bacteria causes a mild stomach illness in young children.
Similarstrain
Note
3
nounnonstandardUS
Another way to write bacterium, meaning one microbe. Common in casual speech, but many people consider it an error.
A bacteria this small can only be seen under a microscope.
The doctor said one bacteria was causing the infection.
Note
4
nounslangderogatorycountable
A nasty, worthless person, used as an insult.
Like calling someone a rat or a snake.
Those bacteria trashed the park and left without cleaning up.
Don't be such a bacteria. Go and apologize to her.
Similarlowlife, scumbag, creep, slimeball
Note

Less common meaning

5
noundatedcountable
Tiny oval-shaped living things, not round and not shaped like a rod.
Like an egg shape compared with a ball or a stick.
Under the microscope the bacteria looked like tiny eggs rather than round balls.
The doctor pointed to the small, oval bacteria on the slide.
Note

bacteria is a form of bacterium

bacterium, noun: A very small living thing made of a single cell, with no center part that holds its genes. Full entry

Forms: bacteriumbacteria plural
Spelling: bacterium → bacteria: irregular plural (no -s)

Practice

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Origins

Meanings 1–4

It comes from New Latin bacteria, from Ancient Greek baktḗrion, meaning "little rod."

Meaning 5

It comes from New Latin bactēria, from Ancient Greek baktēríā, meaning "rod" or "stick."