See virulent in Webster's New World Roget's A-Z Thesaurus II
adjective
Extremely destructive or harmful:
baneful, deadly, malignant, noxious, pernicious, pestilent, pestilential. See helpCapable of injuring or killing by poison:
mephitic, mephitical, poison, poisonous, toxic, toxicant, venomous. See helpBitingly hostile:
acrimonious, bitter, embittered, hard, rancorous, resentful. See attitude, love
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