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.

Put A Letter In One Before Sending It - Brazilian Tour CodyCross Answers | CodyCross Solutions