Original: A sliotar or sliothar (; may derive from Irish sliabh, meaning "mountain" and thar meaning "across") is a hard solid sphere slightly larger than a tennis ball, consisting of a cork core covered by two pieces of leather stitched together.
Simplified: 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.