Painful nonsense about war hero (9)

I believe the answer is:

torturing

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'painful' is the definition.
(similar in meaning)

'nonsense about war hero' is the wordplay.
'nonsense' becomes 'rot' (rot can mean nonsense or rubbish).
'about' says the letters should be written backwards.
'war hero' becomes 'turing' (I can't justify this - if you can you should believe this answer much more).
'rot' backwards is 'tor'.
'tor'+'turing'='TORTURING'

Can you help me to learn more?

(Other definitions for torturing that I've seen before include "Distressing" , "Really hurtful" , "Inflicting great suffering" .)

I've seen this clue in The Independent.

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