Large shade tree (3)
I believe the answer is:
elm
'large shade tree' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elm that I've seen before include "one has a trunk and leaves" , "Tree for a Cockney tiller" , "Strange tree for Mel" , "Deciduous tree with light serrated leaves" , "One [TYPE OF TREE]" .)