Autograph (4)
'autograph' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for signature that I've seen before include "Autograph" , "ending to letter?" , "(In music) the sharps or flats that follow the clef and indicate the key" , "time indicated by this?" , "Identifying script" .)
'autograph' is the definition.
(I know that autograph is a kind of sign)
This is all the clue.
(Other definitions for sign that I've seen before include "Indication; symbol" , "As the star was for 14 across" , "part of the zodiac" , "Ram" , "Traffic control - to write one's name" .)