Again negotiate a withdrawal (7)
I believe the answer is:
retreat
'a withdrawal' is the definition.
(I know that retreat is a type of withdrawal)
'again negotiate' is the wordplay.
'again' becomes 're' (prefix meaning 'again').
'negotiate' becomes 'treat' (I've seen this before).
're'+'treat'='RETREAT'
(Other definitions for retreat that I've seen before include "retirement" , "Leave - refuge" , "care home" , "Back away" , "What cowards might do" .)