Definition from Wiktionary, the free dictionary
berserk (plural berserks)
a crazed Norse warrior who fought in a frenzy
- Injuriously, maniacally, or furiously violent or out of control.
- After he watched his sister stabbed to death, he went berserk and attacked the killer like a beast or a wild animal.
- weird; strange
2017 June 26, Alexis Petridis, “Glastonbury 2017 verdict: Radiohead, Foo Fighters, Lorde, Stormzy and more”, in the Guardian:
- ...the writer conjured up a dystopian fantasy more berserk than anything you might find yourself listening to in the small hours at the Stone Circle.
injuriously, maniacally, or furiously violent or out of control