Emily Dickinson Lexicon

SIG'NA-TURE, n. [Fr. from L. signo, to sign.]

1. A sign, stamp, or mark impressed. The brain being well furnished with various traces, signatures and images. – Watts. The natural and indelible nature of God, stamped on the human soul. – Bentley.
2. In old medical writers, an external mark or character on a plant which was supposed to indicate its suitableness to cure particular disease, or diseases of particular parts. Thus plants with yellow flowers were supposed to be adapted to the cure of jaundice, &c. Some plants bear a very evident signature of their nature and use. – More.
3. A mark for proof, or proof from marks.
4. Sign manual; the name of a person written or subscribed by himself.
5. Among printers, a letter or figure at the bottom of the first page of a sheet or half sheet, by which the sheets are distinguished and their order designated, as a direction to the binder. Every successive sheet has a different letter or figure, and if the sheets are more numerous than the letters of the alphabet, then a small letter is added to the capital one; thus A a, B b. In large volumes, the signatures are sometimes composed of letters and figures; thus 5 A, or 5 B. But some printers now use figures only for signatures.
6. In physiognomy, an external mark or feature by which some persons pretend to discover the nature and qualities of a thing, particularly the temper and genius of persons.
7. In music, the flats and sharps at the beginning of each staff, to mark the key of the movement.