Muscular Christian provides wood (5)
I believe the answer is:
larch
'wood' is the definition.
(I know that larch is a type of wood)
'muscular christian provides' is the wordplay.
'provides' indicates a hidden word.
'LARCH' can be found hidden inside 'muscular christian'.
(Other definitions for larch that I've seen before include "Deciduous conifer" , "wood" , "Supplier of timber" , "Coniferous tree with deciduous bright green needles" .)