Distinctive, characteristic, indicative of identity.

A person's name, written by that person, used as identification or to signify approval of accompanying material, such as a legal contract. / An act of signing one's name; an act of producing a signature.

plural of signature

An isotopic signature

(physics, chemistry) A set of ratios of the abundances of different isotopes of specified elements in a sample, used as a diagnostic test of the sample's origin, or of its age

(music, broadcasting) The tune that opens and/or closes a radio or television programme.

(music) An indication of the key of a composition, giving the number of sharps or flats in the corresponding scale.

(music) A symbol or numerical sign placed on a stave to indicate the meter; in the case of a numerical time signature, the numerator is the number of beats per bar, the denominator represents the value of each beat

plural of e-signature

(Internet) Data used by a signatory to sign something electronically. It may involve cryptography or may simply be a name typed into a document.