What does the word "virus" mean?

The word is from the Latin neuter vīrus referring to poison and other noxious liquids, from 'the same Indo-European base as Sanskrit viṣa poison, Avestan vīša poison, ancient Greek ἰός poison', first attested in English in 1398 in John Trevisa's translation of Bartholomeus Anglicus's De Proprietatibus Rerum. Virulent, from Latin virulentus (poisonous), dates to c. 1400.