Drop building on garden plot, perhaps (4)
I believe the answer is:
shed
'drop' is the definition.
(shedding is a kind of dropping)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for shed that I've seen before include "Jettison" , "Kind of hut - discard it" , "dropped" , "Abandon" , "something at the bottom of the garden?" .)