Emily Dickinson Lexicon

LET'TER, n.² [Fr. lettre; It. litera; L. litera; W. llythyr.]

1. A mark or character, written, printed, engraved or painted; used as the representative of a sound, or of an articulation of the human organs of speech. By sounds, and articulations or closures of the organs are formed syllables and words. Hence a letter is the first element of written language, as a simple sound is the first element of spoken language or speech. As sounds are audible and communicate ideas to others by the ear, so letters are visible representatives of sounds, and communicate the thoughts of others by means of the eye.
2. A written or printed message; an epistle; a communication made by visible characters froth one person to another at a distance. The style of letters ought to be free, easy, and natural. – Walsh.
3. The verbal expression; the literal meaning. We must observe the letter of the law, without doing violence to the reason of the law, and the intentions of the law giver. – Taylor.
4. Type; a character formed of metal or wood, usually of metal, and used in printing books.
5. Letters, in the plural, learning; erudition; as, a man of letters. Dead letter, a writing or precept, which is without authority or force. The best law may become a dead letter. Letter of attorney, a writing by which one person authorizes another to act in his stead. Letter of marque, a private ship commissioned or authorized by a government to make reprisals on the ships of another state. [See Marque.] Letters patent, or overt, open, a writing executed and sealed, by which power and authority are granted to a person to do some act, or enjoy some right; as, letters patent under the seal of England.