Enormous characters in gym, on steroids (7)

I believe the answer is:

monster

'enormous' is the definition.
(thesaurus)

'characters in gym on steroids' is the wordplay.
'characters in' indicates a hidden word.
'MONSTER' is hidden within 'gym on steroids'.

(Other definitions for monster that I've seen before include "Fabled giant animal" , "Inhuman person" , "Vile creature" , "something large and ugly" , "Ogre, demon" .)

I've seen this clue in The Times.

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