/ Dictionary / Index L letter missive: Meaning and Definition of Find definitions for: let'ter mis'sive Pronunciation: [key] — pl. letters missive. a letter from an official source expressing a command, permission, invitation, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. letterman letter of advice Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language