Archipelago or island around north (6)
I believe the answer is:
orkney
'archipelago' is the definition.
(I have seen 'Scottish archipelago ' mean 'orkney' so perhaps 'archipelago' could also mean 'orkney')
'or island around north' is the wordplay.
'island' becomes 'key ' (I've seen this before).
'around' is an insertion indicator.
'north' becomes 'N' (synonyms).
'key' placed around 'n' is 'kney'.
'or'+'kney'='ORKNEY'
(Other definitions for orkney that I've seen before include "-- Islands are off northern Scotland" , "24 ac archipelago" , "Islands across Pentland Firth" , "-- Islands (Scots)" , "Isles north of Pentland Firth" .)