Leaves Kelvin to find wood (4)
I believe the answer is:
teak
'wood' is the definition.
(teak is a kind of wood)
'leaves kelvin' is the wordplay.
'leaves' becomes 'tea' (I've seen this before).
'kelvin' becomes 'k' ('K' can be a synonym of 'kelvin').
'tea'+'k'='TEAK'
'to find' is the link.
(Other definitions for teak that I've seen before include "Strong heavy wood of an Asian tree" , "Type of tree" , "E. Indies hardwood" , "Hardwood tree" , "Hard durable timber" .)