Irreligious person (5)
I believe the answer is:
pagan
'irreligious person' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pagan that I've seen before include "One who does not acknowledge your god(s)" , "advocate of pleasures" , "A heathen, not a Christian" , "Non-mainstream religious believer" , "One who does not acknowledge a god" .)