Meaning

noun your name written in your own handwriting

noun a distinguishing style

noun a melody used to identify a performer or a dance band or radio/tv program

originBorrowed from Middle French signature, or from Medieval Latin signātūra, future active periphrastic of verb signāre from signum (“sign”), + -tūra, feminine of -tūrus, future active periphrastic suffix. Displaced native Old English handseten (literally “hand setting”).

Etymology from Wiktionary, CC BY-SA 3.0