Set criminal on underworld! (8)
I believe the answer is:
hellbent
'set' is the definition.
Both the definition and answer are adjectives.
Maybe there's a link between them I don't understand?
'criminal on underworld' is the wordplay.
'criminal' becomes 'bent' (bent can mean corrupt or criminal).
'on' says to put letters next to each other.
'underworld' becomes 'hell' (synonyms).
'bent' after 'hell' is 'HELLBENT'.
Can you help me to learn more?
(Other definitions for hellbent that I've seen before include "Dogged - persistent" , "Obdurate" , "Determined to achieve something at all costs" , "Utterly determined, on way to perdition" , "Rashly intent" .)