berserk
adjective /bəˈzɜːk/, /bəˈsɜːk/
/bərˈzɜːrk/, /bərˈsɜːrk/
[not usually before noun] (informal)- very angry, often in a violent way or without control
- He went berserk when he found out where I'd been.
- very excited
- People were going berserk with excitement.
Word Originearly 19th cent. (originally as a noun denoting a wild Norse warrior who fought with frenzy): from Old Norse berserkr (noun), probably from birn-, bjorn + serkr ‘coat’, but also possibly from berr ‘bare’ (i.e. without armour).