Tree-climbing included in tradecraft (5)
I believe the answer is:
cedar
'tree' is the definition.
(cedar is a kind of tree)
'climbing included in tradecraft' is the wordplay.
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'included in' says the answer is hidden in the clue.
'radec' is hidden within 'tradecraft'.
'radec' backwards is 'CEDAR'.
(Other definitions for cedar that I've seen before include "Tree (Lebanese?)" , "may have needles?" , "Tree giving fragrant wood" , "representative of Lebanon?" , "Raced around a great hardwood tree" .)