Quiet craftsman is prejudiced (8)
I believe the answer is:
partisan
'is prejudiced' is the definition.
(thesaurus)
'quiet craftsman' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano').
'craftsman' becomes 'artisan' ('artisan' can be a synonym of 'craftsman').
'p'+'artisan'='PARTISAN'
(Other definitions for partisan that I've seen before include "(One) taking one side in dispute" , "Strong party supporter" , "Enthusiast" , "Strongly supporting one side" , "of prejudiced views" .)