returnenvelope
nounUK /rɪˈtɜːn ˌenvələʊp/
US /rɪˈtɝːn ˌenvəloʊp/
An envelope you send back with your reply inside.
Please put the form in the return envelope and mail it today.
OTHER MEANINGS
2. An envelope included with a bill or letter so the receiver can send something back.
The bill came with a return envelope for the payment.
3. An envelope used to send an item back to the sender.
Use the return envelope to send the broken toy back to the store.
4. An envelope printed with the sender's address for replies.
The invitation had a return envelope with the host's address.