NOUN
- mail that includes letters and postcards and packages sealed against inspection
How To Use first-class mail In A Sentence
- On-time is defined as overnight delivery of first-class mail within major cities.
- Send it by first-class mail.
- The fourth-class zone rated parcels and first-class mail have virtually identical historical elasticities.
- The print material is sent via first-class mail the same day the video is sent via third-class mail.
