-nt adjective
Etymology: Middle English, from Latin virulentus, from virus slimy liquid, poison, stench — more at virus
1. : characterized by rapid course, severity, and malignancy — used especially of a disease or infection
2. : extremely poisonous or venomous : deadly , noxious
those mosquitoes must have been particularly virulent — Farmer's Weekly (South Africa)
3. : bitter in enmity : full of malicious hatred : malignant
virulent hostility … thwarted him at every turn — Allen Nevins & H.S.Commager
4. : objectionably and sometimes intolerably harsh or strong
the zeal for culture was equally virulent — T.S.Eliot
wearing a virulent -purple bathrobe — Harold Brodkey
a Mexican port stilled with plague … beneath the virulent sun — Sinclair Lewis
5. : exhibiting virulence : able to overcome or break down the defensive mechanism of the host