The word is from the Latin virus referring to poison and other noxious substances, first used in English in 1392.Virulent, from Latin virulentus (poisonous), dates to 1400.A meaning of agent that causes infectious disease is first recorded in 1728,before the discovery of viruses by Dmitry Ivanovsky in 1892.he English word virus comes from the Latin virus, which means slime or poison: http://dictionary.reference.com/browse/v...