| Answer | Crossword Clue |
|---|---|
| WHOS | Start of a "Knock, knock" response |
| ENTER | "Knock, knock" response |
| ITSOPEN | [Knock, knock] response |
| WHOS | "Knock, knock" response starter |
| JOKE | One might start "Knock knock ..." |
| WHOS | Beginning of a knock-knock answer |
| PUN | Essence of a knock-knock joke |
| WHOS | "... there?" (part of a knock-knock joke) |
| WHO | Word preceding the punch line of a knock-knock joke |
