virulent (adj.)
- acerb
- acerbic
- acid
- acidic
- acidulent
- acidulous
- acrid
- acrimonious
- acute
- antagonistic
- antipathetic
- astringent
- baleful
- baneful
- belligerent
- biting
- bitter
- brutal
- burning
- catching
- caustic
- choleric
- clashing
- communicable
- conflicting
- contagious
- corrosive
- corrupting
- corruptive
- counterproductive
- cutting
- damaging
- dangerous
- deadly
- deathly
- deleterious
- despiteful
- destructive
- detrimental
- disadvantageous
- distressing
- double-edged
- drastic
- edged
- excessive
- exorbitant
- extravagant
- extreme
- fatal
- feral
- fierce
- furious
- great
- harmful
- harsh
- hateful
- hostile
- hurtful
- immoderate
- incisive
- infectious
- infective
- injurious
- intemperate
- intense
- internecine
- keen
- killing
- lethal
- malefic
- malevolent
- malicious
- malign
- malignant
- mephitic
- miasmal
- miasmic
- mischievous
- mordacious
- mordant
- mortal
- nasty
- noisome
- noxious
- ominous
- outrageous
- penetrating
- pernicious
- pestiferous
- pestilential
- piercing
- poignant
- poisonous
- prejudicial
- quarrelsome
- rancorous
- repugnant
- resentful
- rigorous
- rough
- sarcastic
- savage
- scathing
- septic
- severe
- sharp
- sore
- spiteful
- splenetic
- splitting
- stabbing
- stinging
- strident
- stringent
- tart
- tough
- toxic
- toxicant
- trenchant
- unconscionable
- unfriendly
- unhealthy
- unwholesome
- vehement
- venomous
- vicious
- violent
- vitriolic
