Demon kind about brother (4)
I believe the answer is:
monk
'brother' is the definition.
(brother can mean a monk)
'demon kind about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'MONK' can be found hidden inside 'demon kind'.
(Other definitions for monk that I've seen before include "Tonsured person" , "Religious brother" , "prayer?" , "One in a religious order" , "Member of a religious community" .)