RhymeZone: dibs definitions

Definitions of dibs:

noun: (informal) The right to use or enjoy something exclusively or before anyone else.
verb: (informal) To claim a temporary right to (something); to reserve.
noun: (dated) A sweet preparation or treacle of grape juice, much used in the East.
noun: (obsolete) A child's game, played with dib bones or stones, throwing them up from one's palm and catching them on the back of the hand.

(Definitions from Wiktionary)