noun

• (historical) Synonym of berserker (“a Norse warrior who fought in a frenzy”).
  "She had heard of his profligacy, his bursts of fierce Berserk-madness; and yet now these very faults, instead of repelling, seemed to attract her, and intensify her longing to save him."

adj

• (by extension)
  "[T]he writer conjured up a dystopian fantasy more berserk than anything you might find yourself listening to in the small hours at the Stone Circle."
• (by extension)
  "In amongst the strife, Scott McTominay, whose stoppage-time winner against Israel sent Hampden berserk, and Ryan Christie offered signs of an attacking pulse."

verb

• (intransitive) To be or become berserk.
  "When great champions went berserking and were angry, they lost their human nature and went mad like dogs."
• (transitive) To make berserk.
  "He neither knows himself nor his outriders; he berserks a fearful dimension and dismounts, miraculously, in bed!"