To hurt or sting.

“After being hit with a pitch, the batter exclaimed "Ouch, my arm smarts!"”

To cause a smart or sting in.

To feel a pungent pain of mind; to feel sharp pain or grief; be punished severely; to feel the sting of evil.

A sensation that smarts or stings.

Painful, sore.

“My arm is still smarting from where the ball hit it.”

Experiencing emotional pain or embarrassment.