| Clue | Source | Date |
|---|---|---|
| Whack to the head, in slang | New York Times | 25 Jul 2025 |
| Hit upside the head, in slang | New York Times | 28 Aug 2016 |
| Hit upside the head, in slang | ||
| Hit to the back of the head | ||
| Hit upside the head for being a blockhead | ||
| Smack on the back of the head |