What is "sliotar"

n. A hard ball, similar in size to a tennis ball, used in hurling.

A sliotar or sliothar is a hard solid sphere slightly larger than a tennis ball, consisting of a cork core covered by two pieces of leather stitched together. Sometimes called a "dust" or "hurling ball", it resembles a baseball with more pronounced stitching. It is used in the Gaelic games of hurling, camogie, and rounders.