One kind of Muslim (6)
I believe the answer is:
shiite
'one kind of muslim' is the definition.
This is all the clue.
(Other definitions for shiite that I've seen before include "Member of major Islamic group in Iran" , "Member of Muslim sect" , "Member of a branch of Islam" , "Adherent of one branch of Islam" , "Muslim of major Islamic group chiefly in Iran" .)