Forestall gift, having change of heart (7)
I believe the answer is:
prevent
'forestall' is the definition.
(I know that forestall can be written as prevent)
'gift having change of heart' is the wordplay.
I cannot really understand how this works, but
'change' could be 'even' (evening is a kind of changing) and 'even' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for prevent that I've seen before include "Stop from happening" , "Obviate" , "Thwart" , "Avert, hinder" , "Stop, hinder" .)