Religious factions (5)
I believe the answer is:
sects
'religious factions' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sects that I've seen before include "Religious factions" , "Dissenting cliques" , "Groups of people with unconventional religious beliefs" , "Groups of people with divergent religious beliefs" , "Schools of thought" .)