Fierceness shown by assertive he-men? Certainly! (9)

I believe the answer is:

vehemence

'fierceness' is the definition.
(I know that fierceness can be written as vehemence)

'shown by assertive he-men? certainly' is the wordplay.
'shown by' indicates a hidden word.
'VEHEMENCE' is hidden within 'assertive he men certainly'.

(Other definitions for vehemence that I've seen before include "Forcefulness" , "Expression of forceful feeling" , "Vigour of expression" , "Passion" .)

I've seen this clue in The Guardian.

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