| Answer | Crossword Clue |
|---|---|
| NIXY | Letter the Post Office cannot deliver. |
| mailman | person employed by the post office to deliver mail; mail carrier |
| nixie | letter or parcel that is undeliverable by the post office because of a faulty or illegible address |
| nixies | letter or parcel that is undeliverable by the post office because of a faulty or illegible address |
| NIXIE | Undeliverable letter, in post-office slang |
| NIXIE | Undeliverable letter, in post-office talk |
| NIXIE | Dead letter, in post office talk |
| registered | Entrust (a letter or parcel) to a post office for transmission by registered mail |
| registering | Entrust (a letter or parcel) to a post office for transmission by registered mail |
