Meaning

adjective extremely poisonous or injurious; producing venom

adjective infectious; having the ability to cause disease

adjective harsh or corrosive in tone

originPIE word *wisós From Middle English virulent (“leaking or seeping pus, purulent; (of putrefaction) extremely severe (sense uncertain)”) [and other forms], borrowed from Latin vīrulentus (“poisonous”), from vīrus (“poison; venom; slime, slimy liquid; stinking smell; nasty taste”) (ultimately from Proto-Indo-European *wisós (“poison; slime; fluidity”)) + -ulentus (suffix meaning ‘abounding in, full…

Etymology from Wiktionary, CC BY-SA 3.0