Officer in Lada around border going north (7)
I believe the answer is:
admiral
'officer' is the definition.
(admiral is a kind of officer)
'lada around border going north' is the wordplay.
'around' means one lot of letters goes inside another.
'border' becomes 'rim' (both can mean an edge).
'going north' says the letters should be written backwards.
'lada' enclosing 'rim' is 'larimda'.
'larimda' reversed gives 'ADMIRAL'.
'in' is the link.
(Other definitions for admiral that I've seen before include "Commander of the fleet or butterfly" , "Navy bigwig" , "[NELSON] perhaps" , "Red butterfly at sea?" , "High-ranking naval officer like Nelson" .)