Painting perhaps buried in what? Ground (5)
I believe the answer is:
earth
'ground' is the definition.
(synonyms)
'painting perhaps buried in what?' is the wordplay.
'painting perhaps' becomes 'art' (painting is a kind of art).
'buried in' means one lot of letters goes inside another (inserted letters get buried).
'what?' becomes 'eh' (I've seen this in another clue).
'art' inserted inside 'eh' is 'EARTH'.
(Other definitions for earth that I've seen before include "dirt" , "World - soil" , "It is necessary to clear" , "Make electrics safe" , "Soil; ground terminal" .)