Gentle encouragement good in painting? (5)
I believe the answer is:
nudge
'gentle encouragement' is the definition.
(I've seen this before)
'good in painting?' is the wordplay.
'good' becomes 'g' (abbreviation).
'in' is an insertion indicator.
'painting?' becomes 'nude' (nude is a kind of painting).
'g' put within 'nude' is 'NUDGE'.
(Other definitions for nudge that I've seen before include "Jogger" , "Gentle push" , "Festive entertainment" , "---. ---, wink, wink (Monty Python)" , "Push gently" .)