noun
or berserk “
( -s )
Etymology: Old Norse berserkr, from ber- (stem of björn bear) + serkr shirt — more at bear , sark
1. : an ancient Scandinavian warrior reputed to be invulnerable, of enormous strength, and filled with wild frenzy in battle
2. : one whose actions are marked by a headstrong intractable spirit or by reckless defiance (as of orthodox views or attitudes)
a political berserker whose course was completely unpredictable