postmark
🇺🇸
/ˈpəʊstmɑːrk/
🇬🇧
/ˈpəʊstmɑːk/
A stamp that shows where and when a letter was sent.
The postmark on the letter told us it was sent from New York last week.
To stamp a letter with a mark that shows where and when it was sent.
The package was postmarked before it was sent to its destination.