IPA: /ˈɛərəʊɡræm/
KK: /ˈɛrəˌɡræm/
A type of letter that is designed to be sent by air mail. It is made from a thin sheet of paper that can be folded into an envelope, allowing it to be mailed at a lower cost.
I sent my friend an aerogram from my trip abroad.
Aerogram → It is formed from "aero-" (from Greek "aēr", meaning air) and "gram" (from Greek "gramma", meaning something written). The word "aerogram" refers to a message or letter sent through the air, typically by airmail.
Think of 'air' ('aero-') and something 'written' ('gram') to remember that an aerogram is a written message sent through the air.