Wife of Geraint (4)
I believe the answer is:
enid
'wife of geraint' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for enid that I've seen before include "Miss Blyton" , "Geraint's loved one" , "W - - Blyton" , "& 18 Down Children's author" , "Dine with this girl" .)