Faith with Five Pillars (5)
I believe the answer is:
islam
'faith with five pillars' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for islam that I've seen before include "Adherents of a religion" , "Mails to Muslim religion" , "Mails to great eastern religion" , "Creed" , "Mohammed's religion" .)