Bundle of hay or straw (5)
I believe the answer is:
truss
'bundle of hay or straw' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for truss that I've seen before include "Tie up tightly; frame" , "Surgical appliance" , "Hay bundle; tomato cluster" , "Architectural corbel" , "Rusts (anag.)" .)