Border less friendly when North’s overridden South? (8)
I believe the answer is:
frontier
'border' is the definition.
(I know that border can be written as frontier)
'less friendly when north's overridden south?' is the wordplay.
I cannot quite see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is present in the answer.
This explanation may well be incorrect...
(Other definitions for frontier that I've seen before include "Outer edge of a settled territory" , "Wilderness at the edge of a settled area" , "Limit" , "Verge" , "International boundary" .)