1911 Encyclopædia Britannica/Letter
LETTER (through Fr. lettre from Lat. littera or litera, letter of the alphabet; the origin of the Latin word is obscure; it has probably no connexion with the root of linere, to smear, i.e. with wax, for an inscription with a stilus), a character or symbol expressing any one of the elementary sounds into which a spoken word may be analysed, one of the members of an alphabet. As applied to things written, the word follows mainly the meanings of the Latin plural litterae, the most common meaning attaching to the word being that of a written communication from one person to another, an epistle (q.v.). For the means adopted to secure the transmission of letters see Post and Postal Service. The word is also, particularly in the plural, applied to many legal and formal written documents, as in letters patent, letters rogatory and dismissory, &c. The Latin use of the plural is also followed in the employment of “letters” in the sense of literature (q.v.) or learning.