Related Clues:

• Elbow counterpart
• It may be slapped
• It's covered by a cap
• Word with sock or jerk
• Spot for a cap
• Certain joint
• Patella's joint
• Baby bouncer
• '... with a banjo on my ___'
• Place for a cap
• Child support?
• Jerky joint
• Place for a dummy
• Where the femur and tibia meet
• Banjo site, in song