Break down rubbish (3)

I believe the answer is:

rot

I believe this is a double definition.

'break down' is the first definition.
(thesaurus)

'rubbish' is the second definition.
(I've seen this before)

(Other definitions for rot that I've seen before include "crumble" , "Corruption" , "Decay - nonsense" , "Decay in grotesque way" , "Decay or disintegrate" .)

I've seen this clue in The Times and The Telegraph.

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