Antonyms of adj virulent

3 senses of virulent

Sense 1
deadly, venomous, virulent -- (extremely poisonous or injurious; producing venom; "venomous snakes"; "a virulent insect bite")

INDIRECT (VIA toxic) -> nontoxic, atoxic -- (not producing or resulting from poison)

Sense 2
virulent (vs. avirulent) -- (infectious; having the ability to cause disease)

avirulent (vs. virulent) -- (not virulent; unable to produce disease)

Sense 3
acerb, acerbic, acid, acrid, bitter, blistering, caustic, sulfurous, sulphurous, virulent, vitriolic -- (harsh or corrosive in tone; "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation"; "a vitriolic critique")

INDIRECT (VIA unpleasant) -> pleasant -- (affording pleasure; being in harmony with your taste or likings; "we had a pleasant evening together"; "a pleasant scene"; "pleasant sensations")

Similarity of adj virulent

3 senses of virulent

Sense 1
deadly, venomous, virulent -- (extremely poisonous or injurious; producing venom; "venomous snakes"; "a virulent insect bite")
       => toxic (vs. nontoxic) -- (of or relating to or caused by a toxin or poison; "suffering from exposure to toxic substances")

Sense 2
virulent (vs. avirulent) -- (infectious; having the ability to cause disease)
       => highly infective -- ((of a microorganism) extremely infective; "a highly infective organism")
       => deadly -- ((of a disease) having a rapid course and violent effect)

Sense 3
acerb, acerbic, acid, acrid, bitter, blistering, caustic, sulfurous, sulphurous, virulent, vitriolic -- (harsh or corrosive in tone; "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation"; "a vitriolic critique")
       => unpleasant (vs. pleasant) -- (disagreeable to the senses, to the mind, or feelings ; "an unpleasant personality"; "unpleasant repercussions"; "unpleasant odors")