1. a baseball pitch thrown with the fingertips or knuckles that moves unpredictably through the air
Usage: baseball

Examples

• The pitcher threw a knuckler that danced through the strike zone.
• The catcher had trouble handling the knuckler because of its erratic movement.
• His knuckler dropped suddenly just before reaching home plate.
• The veteran pitcher was famous for his devastating knuckler.
• The batter swung and missed at the slow-moving knuckler.
• Few pitchers can master the difficult knuckler grip.