Infidel (7)
I believe the answer is:
heathen
'infidel' is the definition.
(I know that infidel can be written as Heathen)
This is the entire clue.
(Other definitions for heathen that I've seen before include "Non-religious person" , "Person lacking culture or moral principles" , "Godless person" , "Savage" , "Infidel, pagan" .)