bacterium

Definitions

A member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus.

A single-celled prokaryotic organism that can exist as a free-living organism or as a parasite.

Examples

A single bacterium can multiply rapidly under the right conditions.

The scientist examined the bacterium under a high-powered microscope.

Not every bacterium is harmful, as many play essential roles in our digestive system.

Synonyms

microbe germ microorganism bacillus pathogen bug micro-organism

Antonyms

multicellular organism macroscopic organism eukaryote animal plant fungus