Incarcerate fiend with twisted irons (8)

I believe the answer is:

imprison

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'incarcerate' is the definition.
(synonyms)

'fiend with twisted irons' is the wordplay.
'fiend with' becomes 'imp' (I can't explain this - if you can you should believe this answer much more).
'twisted' indicates an anagram.
'irons' with letters rearranged gives 'rison'.
'imp'+'rison'='IMPRISON'

Can you help me to learn more?

(Other definitions for imprison that I've seen before include "Detain" , "put in detention" , "shut up" , "Put away" , "Bang up" .)

I've seen this clue in The Hindu.

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