missive

1. (formal) A written message; a letter, note or memo.Examples: "[Y]ou / Did pocket vp my Letters: and with taunts / Did gibe my Miſive out of audience."; "The juvenile missives from his unmistakably phallic Twitter avatar came days after one of his rockets launched NASA’s first antiasteroid planetary-defense test[…]"; "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."formal

2. (in the plural, Scots law) Letters sent between two parties in which one makes an offer and the other accepts it.in-plural

3. (obsolete) One who is sent; a messenger.Examples: "Whiles I stood rapt in the wonder of it came missives from the King, who all hailed me ‘Thane of Cawdor,’ by which title these Weird Sisters saluted me and referred me to the coming on of time with ‘Hail king that shalt be.’"obsolete