Other forms: airmails
Airmail is post carried abroad by aircraft. Send it airmail, an airmail envelope, by airmail.
The blue-edged envelope and the thin paper existed because weight decided the price, and a letter written on ordinary paper cost noticeably more to send. Almost all international post now flies, so the distinction has quietly disappeared.
1nounairmailPost carried abroad by aircraft.
“She sent the birthday card to Australia by airmail so it would arrive in time.”
airmail is a postal service.
Air plus mail, from the 1920s, when the first regular flying post services began.
From air + mail.
Etymology from Wiktionary, CC BY-SA