virus
n//ˈvaɪ.ɹəs//virus, datorvirus, datavirus
A submicroscopic, non-cellular structure that consists of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and that sometimes causes disease in the host organism (such agents are often classed as nonliving infectious particles and less often as microorganisms).
(informal, metonymically) A disease caused by such an infectious agent; a viral illness.
(computing) 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.