Type of wood needed to make large bow? (5)
I believe the answer is:
larch
'type of wood' is the definition.
(I know that larch is a type of wood)
'large bow?' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'bow?' becomes 'arch' (both can mean to curve).
'l'+'arch'='LARCH'
'needed to make' is the link.
(Other definitions for larch that I've seen before include "Supplier of timber" , "wood" , "Coniferous tree with deciduous bright green needles" , "Deciduous conifer" .)