WEAR THIN

{v.} 1. To become thin from use, wearing, or the passing of time. * /My old pair of pants has worn thin at the knees./ * /This old dime has worn very thin./ 2. To grow less, or less interesting; decrease. * /The joke began to wear thin when you heard it too many times./ * /The teacher's patience began to wear thin when he saw that no one knew the lesson./