Brilliant old man arrests craven one (7)
I believe the answer is:
dastard
'craven one' is the definition.
Both the answer and definition are adjectives. I also know that 'craven' relates to this answer.
'brilliant old man arrests' is the wordplay.
'brilliant' becomes 'star' (I've seen this in other clues).
'old man' becomes 'dad' (synonyms).
'arrests' indicates putting letters inside.
'star' placed into 'dad' is 'DASTARD'.
Can you help me to learn more?
(Other definitions for dastard that I've seen before include "Cowardly fellow" , "despicable fellow!" , "contemptible scaredy-cat" , "Coward" .)