| Answer | Crossword Clue |
|---|---|
| ACES | They're unreturnable |
| ACES | Unreturnable serves |
| KILL | Unreturnable smash |
| ACE | Unreturnable serve |
| ACES | Unreturnable shots |
| SERVICEACE | Unreturnable tennis shot |
| KILL | Unreturnable volleyball shot |
| DEADMAIL | It's undeliverable and unreturnable |
| ACERS | Deliverers of the unreturnable |
| ASIS | Unreturnable, in a way |
