Pop a Card in This and Send It
This page is the CodyCross answer for the clue below from Greece, Group 670, Puzzle 2 (Annual Festivals).
Question is: Pop a Card in This and Send 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.