What is "crown green bowls"

n. (context sports English) A form of bowls, played on a slightly humped, square, grass green, in which two players each play two biased bowls, either along the edges, or diagonally over the crown; it is especially popular in the north of England

Crown Green Bowls (or crown green) is a code of Bowls played outdoors on a grass or artificial turf surface known as a bowling green. The sport's name is derived from the intentionally convex or uneven nature of the bowling green which is traditionally formed with a raised centre known as the crown. Crown Green Bowls is played in the Midlands and Northern half of England, and North Wales.