VIR'ULENT, adjective [Latin virulentus, from virus, poison, that is, strength, from the same root as vir, vireo. See Venom.] 1. Extremely active in doing injury; very poisonous or venomous. No poison is more virulent than that of some species of serpents. 2. Very bitter in enmity; malignant; as a virulent invective.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI