Withdraw demand over time, right? (7)
I believe the answer is:
extract
'withdraw' is the definition.
(thesaurus)
'demand over time right?' is the wordplay.
'demand' becomes 'exact' ('exact' can be a synonym of 'demand'**).
'over' is an insertion indicator.
'time' becomes 't'.
'right?' becomes 'r' (common abbreviation).
't'+'r'='tr'
'exact' placed around 'tr' is 'EXTRACT'.
(Other definitions for extract that I've seen before include "essence" , "Short piece" , "selection" , "concentration" , "(Piece) remove(d)" .)