Put a Letter in One Before Sending It
This page is the CodyCross answer for the clue below from Brazilian Tour, Group 772, Puzzle 4 (São Paulo Nightlife).
Question is: Put a Letter in One Before Sending It
and the answer is: ENVELOPE
Word Meaning:
ENVELOPE — A paper or cardboard wrapper used to enclose small, flat items, especially letters, for mailing.
Definitions from Wiktionary.