Lack of grip shown by apprentice (6)
I believe the answer is:
novice
'apprentice' is the definition.
('novice' can be a synonym of 'apprentice')
'lack of grip' is the wordplay.
'lack of' becomes 'no' (lack of money is no money).
'grip' becomes 'vice' (I've seen this in other clues).
'no'+'vice'='NOVICE'
'shown by' acts as a link.
(Other definitions for novice that I've seen before include "Probationary monk/nun" , "Inexperienced learner" , "Convert" , "Acolyte" , "Rookie" .)