Hearts not affected by point (9)
I believe the answer is:
northeast
'point' is the definition.
(northeast is a kind of point)
'hearts not affected' is the wordplay.
'affected' indicates an anagram.
'hearts'+'not'='heartsnot'
'heartsnot' anagrammed gives 'NORTHEAST'.
'by' is the link.
(Other definitions for northeast that I've seen before include "No threats (anag.)" , "Bearing of forty-five degrees" , "Bearing of 45 degrees" , "Compass point at 45 degrees" , "Belfast is located here" .)