Heathen among propagandists (5)
I believe the answer is:
pagan
'heathen' is the definition.
(both can mean an irreligious person)
'among propagandists' is the wordplay.
'among' says the answer is hidden in the clue.
'PAGAN' can be found hidden inside 'propagandists'.
(Other definitions for pagan that I've seen before include "Unchristian" , "Polytheist" , "advocate of pleasures" , "Pantheistic" , "Person without any conventional religion" .)