- berserk (n.)
- "Norse warrior," 1822, introduced by Sir Walter Scott, from O.N. berserkr (n.) "raging warrior of superhuman strength," probably from *ber- "bear" + serkr "shirt," thus lit. "a warrior clothed in bearskin." The -r was O.N. masc. singular ending, mistaken for agent noun suffix. The adj. is 1867, from such phrases as go berserk.