Servant partly makes up a geisha (4)
I believe the answer is:
page
'servant' is the definition.
(I've seen this before)
'partly makes up a geisha' is the wordplay.
'partly' indicates the answer is hidden within the clue.
'PAGE' can be found hidden inside 'makes up a geisha'.
(Other definitions for page that I've seen before include "Gentleman dwelling at Windsor" , "Attendant - sheet" , "Boy attendant; send out call for" , "Section of biography perhaps" , "servant-boy" .)