missive

Etymology

15th century; from Medieval Latin missīvus, from mittō (“to send”).

noun

1. (formal) A written message; a letter, note or memo.
   The juvenile missives from his unmistakably phallic Twitter avatar came days after one of his rockets launched NASA’s first antiasteroid planetary-defense test[…] December 13 2021, Molly Ball, Jeffrey Kluger, Alejandro de la Garza, “Elon Musk: Person of the Year 2021”, in Time Magazine
   The Madonna letters, which are interspersed with more personal missives in this curious epistolary memoir, accumulate into a rap about the downsides of celebrity - the problems of ageing, of invaded privacy, of becoming vain and impetuously adopting children from other continents. 25 October 2008, Claire Armistead, The Guardian
2. (in the plural, Scotland, law) Letters sent between two parties in which one makes an offer and the other accepts it.
3. (obsolete) One who is sent; a messenger.

adj

1. Specially sent; intended or prepared to be sent.
   a letter missive
   Delivery of the Letters Missive
2. (obsolete) Serving as a missile; intended to be thrown.