Religious ascetic is a sham, as some say (5)
I believe the answer is:
fakir
'religious ascetic' is the definition.
(a fakir is a Muslim ascetic)
'sham as some say' is the wordplay.
'sham' becomes 'faker' (synonyms).
'as some say' indicates a 'sounds like' (homophone) clue.
'faker' sounds like 'FAKIR'.
'is a' acts as a link.
(Other definitions for fakir that I've seen before include "Religious mendicant in India" , "Muslim or Hindu mendicant holy man" , "Ascetic type" , "Muslim mendicant monk and holy man" , "Indian religious ascetic" .)