| Answer | Crossword Clue |
|---|---|
| NIXIE | Undeliverable letter, to postal employees |
| NIXIE | Undeliverable letter, to a postal worker |
| postmark | An official mark stamped on a letter or other postal package, giving the place, date, and time of posting, and serving to cancel the postage stamp |
| postmarks | An official mark stamped on a letter or other postal package, giving the place, date, and time of posting, and serving to cancel the postage stamp |
