Entry 2 senses Webster, 1913 Jackstone · Jack·stone · IPA 01 n. One of the pebbles or pieces used in the game of jackstones. 1. One of the pebbles or pieces used in the game of jackstones. 2. A game played with five small stones or pieces of metal. See 6th Chuck. Also called jacks. See jack{12}, n. Also: jacks See: Chuck, jack