First Known Use: circa 1849
Dictionary
bacterium
noun bac·te·ri·um \bak-ˈtir-ē-əm\
: any one of a group of very small living things that often cause disease
plural -ria \-ē-ə\
Full Definition of BACTERIUM
: any of a domain (Bacteria) of prokaryotic round, spiral, or rod-shaped single-celled microorganisms that may lack cell walls or are gram-positive or gram-negative if they have cell walls, that are often aggregated into colonies or motile by means of flagella, that typically live in soil, water, organic matter, or the bodies of plants and animals, that are usually autotrophic, saprophytic, or parasitic in nutrition, and that are noted for their biochemical effects and pathogenicity; broadly : prokaryote — compare archaea, eukaryote
See bacterium defined for English-language learners
See bacterium defined for kids
ADVERTISEMENT
Origin of BACTERIUM
New Latin, from Greek baktērion staff
Other Microbiology Terms
Rhymes with BACTERIUM
BACTERIUM Defined for Kids
bacterium
noun bac·te·ri·um \bak-ˈtir-ē-əm\
plural bac·te·ria \-ē-ə\
Definition of BACTERIUM for Kids
: any of a group of single-celled microscopic organisms that are important to humans because of their chemical activities and as causes of disease
Medical Dictionary
bacterium
noun bac·te·ri·um \bak-ˈtir-ē-əm\
plural -ria \-ē-ə\
Medical Definition of BACTERIUM
: any of a domain (Bacteria) of prokaryotic round, spiral, or rod-shaped single-celled microorganisms that may lack cell walls or are gram-positive or gram-negative if they have cell walls, that are often aggregated into colonies or motile by means of flagella, that typically live in soil, water, organic matter, or the bodies of plants and animals, that are usually autotrophic, saprophytic, or parasitic in nutrition, and that are noted for their biochemical effects and pathogenicity; broadly : prokaryote
Learn More About BACTERIUM
Browse
Next Word in the Dictionary: bacteriuriaPrevious Word in the Dictionary: bacteriticAll Words Near: bacterium
ADVERTISEMENT
Seen & Heard
What made you want to look up bacterium? Please tell us where you read or heard it (including the quote, if possible).