Piece of furniture, as yet unfinished (4)
I believe the answer is:
easy
'piece' is the definition.
(I have seen 'piece of cake' mean 'easy' so perhaps 'piece' could also mean 'easy')
'of furniture as yet unfinished' is the wordplay.
'of' says the answer is hidden in the clue.
'EASY' is hidden in the letters of 'furniture as yet unfinished'.
(Other definitions for easy that I've seen before include "Posing no difficulty" , "Effortless, uncomplicated" , "Not challenging" , "Achieved without effort" , "Straightforward" .)