n. [ also spelled crackerjack. ] [ prob. from crack + jack, a man. ] 1. An individual of marked ability or excellence, esp. in some sport; as, he is a crackajack at tennis. [ Slang ] Syn. -- jimdandy, jimhickey. [ Webster 1913 Suppl. +PJC ]
2. A preparation of popped corn, candied and pressed into small cakes. The name Cracker Jack(TM) is now a trademark for a similar confection. [ U. S. ] [ Webster 1913 Suppl. +PJC ]
3. something excellent of its kind. Syn. -- jimdandy, jimhickey. [ WordNet 1.5 ]