Waste when teacher with education degree retired (6)
I believe the answer is:
debris
'waste' is the definition.
(I know that debris is a type of rubbish)
'teacher with education degree retired' is the wordplay.
'teacher' becomes 'sir' (way of addressing a male teacher).
'with' is a charade indicator (letters next to each other).
'education degree' becomes 'bed' (I can't justify this - if you can you should believe this answer much more).
'retired' shows that the letters should be reversed in order.
'sir'+'bed'='sirbed'
'sirbed' backwards is 'DEBRIS'.
'when' is the link.
Can you help me to learn more?
(Other definitions for debris that I've seen before include "Brides among rubble" , "Fragments of wreckage" , "Refuse remains" , "Broken remains" , "Brides with pieces of rubble" .)