1. a system of mail delivery by aircraft; postal service using airplanes
Usage: often used attributively (airpost stamp, airpost rate); chiefly historical or in contexts of international mail

Examples

• The airpost service was established to speed up delivery of letters between continents.
• Collectors seek rare airpost stamps from the early aviation era.
• Before modern airmail, the airpost was a luxury service for urgent correspondence.
• The airpost rate was significantly higher than standard ground mail.
• International businesses relied on airpost to send documents quickly overseas.