Injuriously, maniacally, or furiously violent or out of control
1949, Kenneth Douglas, Blanchot and Sartre, in Yale French Studies, No. 3
But after a pretty run of caroms, the lady, shifting her grip on the cue, in a beserk attack brought down its weighted butt on Sartre’s skull.
1987, Marc Blecher, Pacific Affairs, Vol. 60, No. 3
When social science is able to confidently explain why governments sometimes go beserk, much that is novel and important to understand will be added to our disciplined inventory of knowledge