A spare man (7)
I believe the answer is:
ascetic
'a spare man' is the definition.
(someone who lives sparely or simply)
This is all the clue.
(Other definitions for ascetic that I've seen before include "Frugal" , "Severe self-disciplinarian" , "One practising self-denial as a discipline" , "Hermit" , "Severely self-disciplined" .)