Go wild — aggro is terrifying inside (7)

I believe the answer is:

roister

'go wild' is the definition.
(roister can mean to celebrate rowdily)

'aggro is terrifying inside' is the wordplay.
'inside' indicates a hidden word.
'ROISTER' can be found hidden inside 'aggro is terrifying'.

(Other definitions for roister that I've seen before include "Have noisy fun" , "I rest or (anag) - engage in noisy merrymaking" , "Behave boisterously" , "Rioters (anag.)" , "Revel noisily, swagger" .)

I've seen this clue in The Guardian.

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