burkn.

burkburk: [20] Although burk is now the commoner spelling, presumably under the influence of the proper name Burk, the original form of the word was berk. It is short for Berkeley (or perhaps Berkshire) hunt, rhyming slang for cunt. (The Berkeley hunt chases foxes in Gloucestershire.) The pronunciation of the word represents, of course, the dialectal or nonstandard version of Berkeley/Berkshire, rather than the /ba:k/ which became standard in southern British English from the 15th century.