1. the name of a person or a mark or sign representing his name, marked by himself or by an authorized deputy
2. the act of signing one's name
3.
a. a distinctive mark, characteristic, etc., that identifies a person or thing
b. (as modifier) a signature fragrance
4. (Music / Classical Music) Music See key signature, time signature
5. (Medicine / Pharmacology) US the part of a medical prescription that instructs a patient how frequently and in what amounts he should take a drug or agent Abbreviations Sig S
6. (Communication Arts / Printing, Lithography & Bookbinding) Printing
a. a sheet of paper printed with several pages that upon folding will become a section or sections of a book
b. such a sheet so folded
c. a mark, esp a letter, printed on the first page of a signature
[from Old French, from Medieval Latin signātura, from Latin signāre to sign]