1. failed to catch or handle something properly
Usage: informal
2. performed poorly or made a mistake in doing something
Usage: informal

Examples

• The outfielder muffed an easy catch in the ninth inning.
• She muffed her lines during the school play.
• He muffed the job interview by arriving late.
• The goalkeeper muffed the save and let in the winning goal.
• I completely muffed my presentation to the board.
• The receiver muffed the punt and lost the ball.