or aer·o·gram, aer·o·gramme
[ air-uh-gram ]
/ ˈɛər əˌgræm /
a sheet of lightweight paper, bearing an official postal stamp imprint, that is folded to form its own envelope and can be sent via airmail at a special, low rate because of its standard size, light weight, and lack of enclosures.
Compare air letter.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019