The type of Male pattern baldness, as exhibited by Jim from the Australian soap Neighbours in the late 80s-early 90s.
This is characterised by a hairline that has receded at the front, to the point where there is a small island of hair left at the top of the forehead.
This may be connected to the main hair by a little causeway. In that case it would become a peninsula.
Boy, Joe really needs to get rid of that jim from neighbours island, he's starting to look like little Jimmy Somerville.