Virus
/ˈvaɪrəs/noun
An infectious agent that can replicate only inside the living cells of an organism.
Did you know?Latin virus originally meant a poisonous slime or venom, and English later reused it for infectious agents because they seemed like a kind of invisible toxic contagion.
Etymological Timeline
Classical Latin
Latin
virus
“poison, venom, slimy liquid”
Late Latin
Latin
virus
“poisonous substance, noxious secretion”
16th Century
English
virus
“a poisonous agent or noxious substance”
19th Century
English
virus
“the infectious agent causing disease”
Modern English
English
virus
“an infectious agent that replicates only inside living cells”