from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fool, prat, twit.
- n. An idiot, in an affectionate sense.
- n. Cunt.
The usage is dated to the 1930s. A shortened version of Berkeley Hunt, the hunt based at Berkeley Castle in Gloucestershire. In the Cockney rhyming slang, hunt is used as a rhyme for cunt giving the word berk its original slang meaning. (Wiktionary)