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bacteria

[bak-teer-ee-uh]
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plural noun, singular bac·te·ri·um [bak-teer-ee-uh m] /bækˈtɪər i əm/.
  1. ubiquitous one-celled organisms, spherical, spiral, or rod-shaped and appearing singly or in chains, comprising the Schizomycota, a phylum of the kingdom Monera (in some classification systems the plant class Schizomycetes), various species of which are involved in fermentation, putrefaction, infectious diseases, or nitrogen fixation.
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Origin of bacteria

1905–10; < New Latin < Greek baktḗria, plural of baktḗrion; see bacterium
Related formsbac·te·ri·al, adjectivebac·te·ri·al·ly, adverbnon·bac·te·ri·al, adjectivenon·bac·te·ri·al·ly, adverbun·bac·te·ri·al, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for bacteria

pathogens, germs, bacilli

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British Dictionary definitions for bacteria

bacteria

pl n singular -rium (-rɪəm)
  1. a very large group of microorganisms comprising one of the three domains of living organisms. They are prokaryotic, unicellular, and either free-living in soil or water or parasites of plants or animalsSee also prokaryote
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Derived Formsbacterial, adjectivebacterially, adverb

Word Origin for bacteria

C19: plural of New Latin bacterium, from Greek baktērion, literally: a little stick, from baktron rod, staff
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for bacteria

n.

1847, plural of Modern Latin bacterium, from Greek bakterion "small staff," diminutive of baktron "stick, rod," from PIE *bak- "staff used for support." So called because the first ones observed were rod-shaped. Introduced as a scientific word 1838 by German naturalist Christian Gottfried Ehrenberg (1795-1876).

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Online Etymology Dictionary, © 2010 Douglas Harper

bacteria in Medicine

bacteria

(băk-tîrē-ə)
n.
  1. Plural ofbacterium
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

bacteria in Science

bacteria

[băk-tîrē-ə]
  1. Plural of bacterium.
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bacterium

[băk-tîrē-əm]
Plural bacteria
  1. 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. See also archaeon prokaryote.
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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.
Related formsbacterial adjective
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

bacteria in Culture

bacteria

sing. bacterium

Microorganisms made up of a single cell that has no distinct nucleus. Bacteria reproduce by fission or by forming spores.

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Note

Some bacteria are beneficial to humans (for example, those that live in the stomach and aid digestion), and some are harmful (for example, those that cause disease).
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.