0 abbreviation for self-addressed stamped envelope: an envelope with a stamp and your name and address on it that you send inside another envelope to an organization when you want a reply: --
Please enclose an SASE with your application.
1 abbreviation for self-addressed stamped envelope (= an envelope that has a stamp on it and the address of the person who sends it) --
2 abbreviation for self-addressed stamped envelope: an envelope with your name, address, and a stamp on, that you send to someone so that they can send you something back: --