The digit or figure 9.
A playing card with nine pips.
A nine-millimeter semi-automatic pistol.
(usually in the plural) A statistical unit of proportion (of reliability, purity, etc.).
They guaranteed that our Web site would have 99.99% uptime, or four nines.
A baseball club, team, or lineup (composed of nine players).
A pair of nines.
He drew nines from the deck.