Girl fed it hay, partly (5)
I believe the answer is:
edith
'girl' is the definition.
(I've seen this before)
'fed it hay partly' is the wordplay.
'partly' indicates a hidden word.
'EDITH' is hidden in the letters of 'fed it hay'.
(Other definitions for edith that I've seen before include "- - Piaf, singer" , "Dame ----- Evans (1888-1976), stage and screen actress" , "Dame - Sitwell, English poet (Facade)" , "Woman" , "girl" .)