Due to victory, go back outside (5)
I believe the answer is:
owing
'due to' is the definition.
(owing money)
'victory go back outside' is the wordplay.
'victory' becomes 'win' (a win is a victory).
'back' says the letters should be written backwards.
'outside' is an insertion indicator.
'go' written backwards gives 'og'.
'win' going into 'og' is 'OWING'.
(Other definitions for owing that I've seen before include "Outstanding as a debt" , "Unsettled; on account" , "Undischarged" , "Due to, like debt" , "(Of money) outstanding" .)