Structure supporting weight beneath large tree (5)
I believe the answer is:
larch
'tree' is the definition.
(larch is a kind of tree)
'structure supporting weight beneath large' is the wordplay.
I cannot quite see how this works, but
'structure' could be 'arch' (arch is a kind of structure) and 'arch' is found in the answer.
'large' could be 'l' (eg in clothes sizes) and 'l' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for larch that I've seen before include "Supplier of timber" , "Deciduous conifer" , "Coniferous tree with deciduous bright green needles" , "wood" .)