Piece of artwork needed to provide support for a proposal? (4)
I believe the answer is:
knee
'support for a proposal?' is the definition.
(I've seen this in another clue)
'piece of artwork needed to' is the wordplay.
'piece of' indicates the answer is hidden within the clue.
'KNEE' is hidden within 'artwork needed to'.
'provide' acts as a link.
(Other definitions for knee that I've seen before include "Joint of the body" , "Human joint" , "One bent in genuflection" , "Flexible joint" , "may present problem to maid" .)