[adv] in a murderous frenzy; "rioters running amuck and throwing sticks and bottles and stones"
[adv] wildly; without self-control; "when the restaurant caught fire the patrons ran amuck, blocking the exit"
[adj] in a murderous frenzy as if possessed by a demon; "the soldier was completely amuck"; "berserk with grief"; "a berserk worker smashing windows"