adj.
Pronunciation: b ə (r)- ' s ə rk, ˌ b ə r-, - ' z ə rk; ' b ə r- ˌ
Variant: or ber · serk · er \ - ' s ə r-k ə r, - ' z ə r-; ' b ə r- ˌ \
Function: noun
Etymology: Old Norse berserkr, probably from ber- bear + serkr shirt
Date: 1818
1 : an ancient Scandinavian warrior frenzied in battle and held to be invulnerable
2 : one whose actions are recklessly defiant