Lives on the borders (7)
I believe the answer is:
resides
'lives' is the definition.
(to reside somewhere is to live there)
'on the borders' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'the borders' becomes 'sides' (I've seen this in another clue).
're'+'sides'='RESIDES'
(Other definitions for resides that I've seen before include "Lives, dwells" , "stays required" , "stays in Peebles" , "Sojourns" , "stayed in Scotland" .)