In carnival knock back Muslim ascetic? (5)
I believe the answer is:
fakir
'muslim ascetic?' is the definition.
(I've seen this before)
'in carnival knock back' is the wordplay.
'in' means one lot of letters goes inside another.
'carnival' becomes 'fair' (synonyms).
'back' indicates one should take the final letters.
The last letter of 'knock' is 'k'.
'fair' placed around 'k' is 'FAKIR'.
(Other definitions for fakir that I've seen before include "Religious mendicant in India" , "Muslim ascetic - Hindu holy man" , "Indian religious ascetic" , "Eastern holy man" , "Holy man of the East" .)