A hundred right prior to a setback with packing boxes (6)
I believe the answer is:
crates
'packing boxes' is the definition.
(I've seen this in another clue)
'a hundred right prior to a setback' is the wordplay.
'a hundred' becomes 'C' (Roman numeral).
'right' becomes 'ra' (I can't explain this - if you can you should believe this answer much more).
'prior to' is a charade indicator (letters next to each other).
'a setback' becomes 'tes' (I've seen this in other clues).
'c'+'ra'+'tes'='CRATES'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for crates that I've seen before include "Jalopies" , "Packing cases" , "Boxes for shipping goods" , "Rough wooden boxes" .)