bacterium
Americannoun
noun
plural
bacteria-
Any of a large group of one-celled organisms that lack a cell nucleus, reproduce by fission or by forming spores, and in some cases cause disease. They are the most abundant lifeforms on Earth, and are found in all living things and in all of the Earth's environments. Bacteria usually live off other organisms. Bacteria make up most of the kingdom of prokaryotes (Monera or Prokaryota), with one group (the archaea) sometimes classified as a separate kingdom.
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See also archaeon prokaryote
Usage
It is important to remember that bacteria is the plural of bacterium, and that saying a bacteria is incorrect. It is correct to say The soil sample contains millions of bacteria, and Tetanus is caused by a bacterium.
Etymology
Origin of bacterium
1840–50; < New Latin < Greek baktḗrion, diminutive of baktēría staff; akin to báktron stick, Latin baculum, bacillum
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"So, we are now colonizing that central space, and the bacterium is essentially ridding the body of the tumor."
From Science Daily
Instead of copying part of a virus or bacterium, this new vaccine imitates the communication signals immune cells exchange during infection.
From Science Daily
A common respiratory bacterium that typically causes pneumonia and sinus infections may also play a role in Alzheimer's disease.
From Science Daily
This bacterium is a well known cause of hospital acquired pneumonia and bloodstream infections and is especially difficult to treat.
From Science Daily
Cholera is an acute intestinal infection that spreads through food and water contaminated with the bacterium vibrio cholerae, often from faeces.
From Barron's
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
