Jimmy White's white?

• It's white with no number
• You can scratch with it
• It's struck in snooker
• Pool necessity
• Billiard item
• Shark's target?
• Object struck by a snooker player
• Item seldom seen in pockets
• When you pocket it, you scratch

Wiktionary Word definitions in Wiktionary
n. (alternative spelling of cue ball English)