Able to sell radio for scrap (6)
I believe the answer is:
cancel
'for scrap' is the definition.
(I've seen this before)
'able to sell radio' is the wordplay.
'able' becomes 'can'.
'to sell radio' becomes 'cel' (I can't justify this - if you can you should believe this answer much more).
'can'+'cel'='CANCEL'
Can you help me to learn more?
(Other definitions for cancel that I've seen before include "Cross out or annul" , "Go for an annulment" , "Annul, revoke" , "Annul or rescind" , "Officially prevent happening" .)