virus
noun
[ ˈvʌɪrəs ]
• an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.
• "the hepatitis B virus"
• a piece of code which is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data.
Origin:
late Middle English (denoting the venom of a snake): from Latin, literally ‘slimy liquid, poison’. The earlier medical sense, superseded by the current use as a result of improved scientific understanding, was ‘a substance produced in the body as the result of disease, especially one capable of infecting others’.
