From Old Norse 'berserkr' (bear-shirt) — Norse warriors who fought in ecstatic fury, believed impervious to pain, devoted to Odin.
Out of control with anger or excitement; wildly frenzied.
From Old Norse 'berserkr,' a type of Norse warrior who fought in a trance-like fury. The word is traditionally explained as 'bear-shirt' (from 'ber-' bear + 'serkr' shirt/coat), referring to warriors who wore bearskins into battle. An alternative etymology derives the first element from 'berr' (bare), suggesting they fought without