Humble style associated with holy man (6)
I believe the answer is:
modest
'humble' is the definition.
(I know that humble can be written as modest)
'style associated with holy man' is the wordplay.
'style' becomes 'mode' (synonyms).
'associated with' says to put letters next to each other.
'holy man' becomes 'st' (abbreviation for saint).
'mode'+'st'='MODEST'
(Other definitions for modest that I've seen before include "Reserved" , "Mussorgsky, nominally?" , "Not vain, rather shy" , "Decorous" , "retiring" .)