WordWeb Online

1. Someone excellent of their kind
   "he's a jimdandy of a soldier";
   - jimhickey, crackerjack
    
2. Something excellent of its kind
   "the bike was a jimdandy";
   - crackerjack

Derived forms: jimdandies

Type of: apotheosis, ideal, nonesuch [archaic], nonpareil, nonsuch [archaic], paragon, saint, thing