Wood used in pelmet (3)
I believe the answer is:
elm
'wood' is the definition.
(elm is a kind of wood)
'in pelmet' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ELM' is hidden in the letters of 'pelmet'.
'used' acts as a link.
(Other definitions for elm that I've seen before include "Species of tree" , "Native British tree" , "Hard wood" , "Deciduous tree with rough serrated leaves" , "Tree for a Cockney tiller" .)