Back track round north and south (7)
I believe the answer is:
sponsor
'back' is the definition.
(I've seen this before)
'track round north and south' is the wordplay.
'track' becomes 'spoor' (spoor is a kind of track).
'round' indicates putting letters inside.
'north' becomes 'N' (abbreviation).
'and' says to put letters next to each other.
'south' becomes 'S' (abbreviation).
'n'+'s'='ns'
'spoor' enclosing 'ns' is 'SPONSOR'.
(Other definitions for sponsor that I've seen before include "Supporter or champion" , "One pledging money" , "Promoter, godparent" , "Godparent at a baptism" , "Help fund a sporting or artistic event" .)