Take legal action to cover rubbish monument (6)
I believe the answer is:
statue
'monument' is the definition.
(I've seen this before)
'take legal action to cover rubbish' is the wordplay.
'take legal action' becomes 'sue' (I've seen this before).
'to cover' means one lot of letters goes inside another.
'rubbish' becomes 'tat' (low-quality items or material).
'sue' enclosing 'tat' is 'STATUE'.
(Other definitions for statue that I've seen before include "Artistic work" , "A carved or moulded effigy" , "artwork" , "Sculpture representing a human or animal" , "Sculptured figure" .)