Nimble artist federation’s holding back (4)
I believe the answer is:
deft
'nimble' is the definition.
(I've seen this before)
'artist federation's holding back' is the wordplay.
'holding' indicates a hidden word.
'back' says the letters should be written backwards.
'tfed' is hidden in the letters of 'artist federations'.
'tfed' written backwards gives 'DEFT'.
(Other definitions for deft that I've seen before include "Manually skilful, handling things neatly" , "Handling things skilfully or neatly" , "Dextrous" , "Handy" , "Adroit, dexterous" .)