Tree leaves in a bag, king? (4)
I believe the answer is:
teak
'tree' is the definition.
(teak is a kind of tree)
'leaves in a bag king?' is the wordplay.
'leaves in a bag' becomes 'tea' (I've seen this in another clue).
'king?' becomes 'k' (abbreviation for king in chess).
'tea'+'k'='TEAK'
(Other definitions for teak that I've seen before include "Type of tree" , "Heavy wood of a tall evergreen Asian tree" , "Hardwood tree" , "Take away with very hard wood" , "Type of wood" .)