A stinging blow is a physical or emotional attack that causes pain or distress. The term can be used to describe a physical SLAP, which is a four-letter word. A SLAP is a quick, sharp hit with the open hand, usually to the face or head, and it can be used as a form of punishment or discipline. It can also be used to express anger or frustration. Slapping someone can leave a lasting impression, both physically and emotionally, and can be considered a stinging blow.