A tyro without fault (6)
I believe the answer is:
novice
'a tyro' is the definition.
('novice' can be a synonym of 'tyro')
'without fault' is the wordplay.
'without' becomes 'no'.
'fault' becomes 'vice' (I've seen this before).
'no'+'vice'='NOVICE'
(Other definitions for novice that I've seen before include "Beginner, learner" , "New member (of religious order)" , "New starter" , "Salvage" , "Trainee monk" .)