Fan of austerity called out as an inflexible parasite (7)
I believe the answer is:
ascetic
'fan of austerity' is the definition.
(an ascetic lives in an austere way)
'called out as an inflexible parasite' is the wordplay.
I cannot quite understand how this works, but
'as' is within the answer.
'an' could be 'i' (Roman numeral for one) and 'i' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ascetic that I've seen before include "One practises self-denial as a spiritual discipline" , "Self-denying, not allowing oneself luxuries" , "Frugal" , "Austere disciple" , "Severely self-disciplined" .)