Iterates awfully formal piece of writing (8)

I believe the answer is:

treatise

'formal piece of writing' is the definition.
(I've seen this before)

'iterates awfully' is the wordplay.
'awfully' indicates an anagram.
'iterates' anagrammed gives 'TREATISE'.

(Other definitions for treatise that I've seen before include "Long, detailed essay" , "Learned paper" , "Disquisition" , "Written exposition of an argument" , "Learned writing" .)

I've seen this clue in The Telegraph.

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