virus

noun

1. 1.A submicroscopic, non-cellular structure consisting of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and often causes disease in the host organism.
2. 2.A disease caused by these organisms.
3. 3.Venom, as produced by a poisonous animal etc.
4. 4.A type of malware which can covertly transmit itself between computers via networks (especially the Internet) or removable storage such as disks, often causing damage to systems and data; also computer virus.
5. 5.Any type of malware.