Hanger-on in French city initially expecting pay back (9)
I believe the answer is:
reimburse
'pay back' is the definition.
(I've seen this before)
'hanger-on in french city initially expecting' is the wordplay.
'hanger-on' becomes 'bur' (type of seed which hangs onto clothing).
'in' means one lot of letters goes inside another.
'french city' becomes 'reims' (I've seen this before).
'initially' indicates taking the first letters.
The initial letter of 'expecting' is 'e'.
'bur' going into 'reims' is 'reimburs'.
'reimburs'+'e'='REIMBURSE'
(Other definitions for reimburse that I've seen before include "Repay - reuse brim" , "Pay back (e.g. expenses)" , "Compensate for money already spent" , "Repay a person who has spent or lost money" , "refund" .)