Start, say, to give up (4)
I believe the answer is:
cede
'give up' is the definition.
(I know that give up can be written as cede)
'start say' is the wordplay.
'start' becomes 'seed' (I've seen this in another clue).
'say' indicates a 'sounds like' (homophone) clue.
'seed' is a homophone of 'CEDE'.
'to' is the link.
(Other definitions for cede that I've seen before include "Give up one's rights" , "Yield or give up to another" , "Reluctantly give up" , "Surrender or yield" , "Give away" .)