berserk

Origin

The noun is borrowed from Old Norse berserkr (“Norse warrior who fights in a frenzy”), probably from bjǫrn (“bear”) + serkr (“coat; shirt”), referring to the bearskins which the warriors wore. Bjǫrn is possibly ultimately derived from Proto-Indo-European *bʰerH- (“brown”); and serkr from Proto-Indo-European *ser- (“to bind, tie together; thread”). Alternatively, it has been suggested that the first element of the word is from berr (“bare, naked”), referring to warriors who went into battle without armour, but this is now thought unlikely. Doublet of berserker. The adjective is derived from the noun.