bacterium

[bak-teer-ee-uh m] /bækˈtɪər i əm/

noun

singular of bacteria.

Origin

1840-50; < Neo-Latin < Greek baktḗrion, diminutive of baktēría staff; akin to báktron stick, Latin baculum, bacillum

bacteria

[bak-teer-ee-uh] /bækˈtɪər i ə/

plural noun, singular bacterium

[bak-teer-ee-uh m] /bækˈtɪər i əm/ (Show IPA)

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.

Origin

1905-10; < Neo-Latin < Greek baktḗria, plural of baktḗrion; see bacterium

Related forms

bacterial, adjective

bacterially, adverb

nonbacterial, adjective

nonbacterially, adverb

unbacterial, adjective

Examples from the web for bacterium

The typical safety office will monitor biohazards produced from research on, say, a virulent virus or bacterium.
Also, the lymphoid tissue of the stomach can produce a low-grade gastric lymphoma under the influence of this bacterium.
The high cost of treating human wastewater may one day tank thanks to a bacterium that eats ammonia and produces rocket fuel.
They think a particular sort of bacterium might alleviate clinical depression.
In this context patenting an artificial genome for a bacterium seems reasonable.
The bacterium doesn't much affect the creatures, which serve as a reservoir for the disease.
Insulin, for instance, has long been made by putting the human gene for it into a helpful bacterium.
They also engineer two genes--one from a type of yeast, one from a cheese-making bacterium--into the microbe.
Researchers isolated a set of bacterium to do the filtering, and they've now patented that combination.
Sometimes it kills the bacterium responsible for dental plaque.

British Dictionary definitions for bacterium

bacterium

/bækˈtɪərɪəm/

noun

the singular of bacteria

bacteria

/bækˈtɪərɪə/

plural noun (sing) -rium (-rɪəm)

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 animals See also prokaryote

Derived Forms

bacterial, adjective
bacterially, adverb

Word Origin

C19: plural of New Latin bacterium, from Greek baktērion, literally: a little stick, from baktron rod, staff

Word Origin and History for bacterium

c.1848, singular of bacteria (q.v.).

bacteria

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).

bacterium in Medicine

bacteria bac·te·ri·a (bāk-tǐr'ē-ə)
n.
Plural of bacterium.

bac·te'ri·al adj.

bacterium bac·te·ri·um (bāk-tēr'ē-əm)
n. pl. bac·te·ri·a (-tēr'ē-ə)
Any of the unicellular, prokaryotic microorganisms of the class Schizomycetes, which vary in terms of morphology, oxygen and nutritional requirements, and motility, and may be free-living, saprophytic, or pathogenic, the latter causing disease in plants or animals.

bacterium in Science

bacteria

(bāk-tîr'ē-ə)
Plural of bacterium.

bacterium

(bāk-tîr'ē-əm)
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 or archaebacteria) often classified as a separate kingdom. See also archaeon, prokaryote.

bacterial adjective

Our Living Language : 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.

bacterium in Culture

bacteria definition

sing. bacterium

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

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).