1. Plaything consisting of a toy figure with movable joints that can be made to dance by pulling strings
   "The children laughed as they made the jumping jack dance"
    
2. A calisthenic exercise performed by jumping to a position with legs spread wide and arms raised overhead, then returning to a position with legs together and arms at sides
   "The class did fifty jumping jacks as a warm-up"

Derived forms: jumping jacks

Type of: plaything, toy

Encyclopedia: Jumping jack