Sell up when independence goes, not before (5)
I believe the answer is:
later
'before' is the definition.
Both the definition and answer are adverbs. Maybe there's an association between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for later that I've seen before include "Tardier" , "after an interval" , "behind schedule" , "Alert (anag.)" , "At some time afterwards" .)