berserk
From Longman Dictionary of Contemporary Englishberserkber‧serk /bɜːˈsɜːk, bə- $ bɜːrˈsɜːrk, ˈbɜːrsɜːrk/ adjective → go berserkExamples from the Corpusberserk• But how can our uppermost tier go so berserk?• Toos threw unending series of berserk punches, ignoring incoming rounds as if they were raindrops on a pleasant spring day.Origin berserk (1800-1900) Old Norse berserkr “wild fighter”, from björn “bear” + serkr “shirt”