Withdraw extremely remote flag (6)
I believe the answer is:
retire
'withdraw' is the definition.
('retire' can be a synonym of 'withdraw')
'extremely remote flag' is the wordplay.
'extremely' suggests removing the centre.
'flag' becomes 'tire' (I've seen this before).
'remote' with its centre removed is 're'.
're'+'tire'='RETIRE'
(Other definitions for retire that I've seen before include "Stop work - go to bed" , "call it a day" , "Finish following one's career" , "Withdraw - give up work - go to bed" , "retreat" .)