aerogramme

/EH0 R OW0 G R AE0 M/
noun
  1. 1

    A wireless message.

  2. 2

    A telegram whose transmission included at least one segment sent via airplane.

  3. 3

    A thin piece of foldable and gummed paper for writing a letter and serving as its own envelope for transit via airmail.

  4. 4

    A pneumogram.

Source: https://en.wiktionary.org/wiki/aerogram, https://en.wiktionary.org/wiki/aerogramme