1. lightweight airmail letters that fold to form their own envelopes
Usage: plural form; primarily historical

Examples

• My grandmother sent aerogrammes from Europe during her travels.
• The post office sold aerogrammes for international correspondence.
• Aerogrammes were popular before email became widespread.
• He collected vintage aerogrammes from different countries.
• The thin blue aerogrammes could be folded and sealed without envelopes.
• International aerogrammes had standardized postage rates.
• She wrote long letters on aerogrammes to save on postage costs.