Definition of Virus:
(VYE-rus) A microorganism that can infect cells and cause disease.

A term for a group of infectious agents which with few exceptions are capable of passing through fine filters that retain most bacteria, are usually not visible through the light microscope, lack independent metabolism, and are incapable of growth or reproduction apart from living cells.
Virus is part of the Organisms group
Related Terms
DNA Virus
Other Virus Grouping
RNA Virus
Retro-transcribing Virus
Virus-like Particle