Watson who played Hermione (4)
I believe the answer is:
emma
'watson who played hermione' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for emma that I've seen before include "companion for Pip" , "Titled heroine" , "Jane Austen novel and Nelson's lover" , "Lady - Hamilton, mistress of Nelson" , "novelist's work" .)