The amount of room to spare for the disposal of surplus goods (9)
I believe the answer is:
clearance
'disposal of surplus goods' is the definition.
'clearance' can be an answer for 'disposal' (thesaurus). I am not sure about the 'of surplus goods' bit.
'the amount of room to spare' is the wordplay.
I cannot quite see how this works, but
'amount' could be 'lea' (lea is a kind of amount) and 'lea' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for clearance that I've seen before include "Official authorisation" , "Permission to proceed" , "demolition" , "Sanction" , "Eviction from lands" .)