Hearts not changing direction (9)
I believe the answer is:
northeast
'direction' is the definition.
(I know that northeast is a type of direction)
'hearts not changing' is the wordplay.
'changing' indicates anagramming the letters.
'hearts'+'not'='heartsnot'
'heartsnot' anagrammed gives 'NORTHEAST'.
(Other definitions for northeast that I've seen before include "Bearing of 45 degrees" , "Compass point at 45 degrees" , "Direction" , "Bearing of forty-five degrees" , "No threats (anag.)" .)