County secure, on track (7)
I believe the answer is:
rutland
'county' is the definition.
(I know that Rutland is a county)
'secure on track' is the wordplay.
'secure' becomes 'land' (land can mean to secure or obtain).
'on' says to put letters next to each other.
'track' becomes 'rut' (rut is a kind of track).
'land' after 'rut' is 'RUTLAND'.
(Other definitions for rutland that I've seen before include "East Midlands county" , "Smallest English county" , "Smallest of the historical English counties" , "Small English county" , "Tiny county" .)