Dump something? Yes, in the depot (7)
I believe the answer is:
deposit
'dump' is the definition.
(thesaurus)
'yes in the depot' is the wordplay.
'yes' becomes 'si' (I can't justify this - if you can you should believe this answer much more).
'in the' means one lot of letters goes inside another.
'si' placed inside 'depot' is 'DEPOSIT'.
'something?' acts as a link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for deposit that I've seen before include "Put money into a bank account" , "First instalment" , "Down-payment" , "Plant" , "Topside (anag) - put down" .)