virus Definition

virus
noun

1. An infectious particle, consisting of a core of DNA or RNA enclosed in a protein shell, only visible under an electron microscope, that invades the cells of animals, plants and bacteria, and can only survive and reproduce within such cells.
2. The organism that causes and transmits an infectious disease.

Thesaurus: germ, micro-organism, bug.
3. loosely
A disease caused by such an organism.
Thesaurus: sickness, illness, infection, bug (slang).
4. Anything that damages or corrupts.
5. A self-replicating program that attaches to a computer system, spreading to other systems via a network and when activated, often at a later date, can corrupt or destroy data stored on the hard disk.

Form: computer virus (in full)

Derivative: viral

See separate entry.

Etymology: 16c: Latin, meaning ‘slimy liquid'.