Will, if you forsake (5)
I believe the answer is:
leave
This could be a double definition.
'will' is the first definition.
(synonyms)
'forsake' is the second definition.
(I've seen this in another clue)
'if you' is the link.
This may not be right. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for leave that I've seen before include "Break" , "Desert" , "Go (5)" , "ditch" , "Depart on work holiday?" .)