Englishvicious
adjective
1 there was a vicious killer at large:
brutal, ferocious, savage, violent, dangerous, ruthless, remorseless, merciless, heartless, callous, cruel, harsh, cold-blooded, inhuman, fierce, barbarous, barbaric, brutish, bestial, bloodthirsty, bloody, fiendish, sadistic, monstrous, villainous, murderous, homicidal, heinous, atrocious, diabolical, terrible, dreadful, awful, grim;
British, informal beastly;
archaic fell, sanguinary.
▷antonyms gentle.
2 the MP was the victim of a vicious hate campaign:
malicious, malevolent, malignant, malign, spiteful, vindictive, venomous, poisonous, baleful, virulent, pernicious, backbiting, rancorous, caustic, mean, cruel, bitter, acrimonious, hostile, hate-filled, menacing, nasty, unpleasant, evil;
defamatory, slanderous;
informal bitchy, catty;
literary malefic, maleficent.
▷antonyms kindly, benevolent.
vicious Oxford Dictionary of English