Partly coppiced a redwood tree (5)
I believe the answer is:
cedar
'tree' is the definition.
(cedar tree is a kind of tree)
'partly coppiced a redwood' is the wordplay.
'partly' says the answer is hidden in the clue.
'CEDAR' is hidden in the letters of 'coppiced a redwood'.
(Other definitions for cedar that I've seen before include "Tall coniferous tree" , "Fragrant conifer" , "Raced around a great hardwood tree" , "Great hardwood tree associated with Lebanon" , "may have needles?" .)