Shilling amateur put in to get free painting (8)
I believe the answer is:
seascape
'painting' is the definition.
(seascape is a kind of painting)
'shilling amateur put in to get free' is the wordplay.
'shilling' becomes 's'.
'amateur' becomes 'a'.
'put in' means one lot of letters goes inside another.
'to get free' becomes 'escape' (I've seen this before).
'a' put inside 'escape' is 'eascape'.
's'+'eascape'='SEASCAPE'
(Other definitions for seascape that I've seen before include "Painting - pea cases (anag)" , "off the coast?" , "Maritime picture" , "Maritime scene" , "Marine view/picture" .)