Looking angry, fellow being caught and put back inside (6)
I believe the answer is:
remand
'put back inside' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'looking angry fellow being caught' is the wordplay.
'looking angry' becomes 'red' (someone may go red when angry).
'fellow' becomes 'man' (fellow can mean a man).
'being caught' is an insertion indicator.
'red' placed around 'man' is 'REMAND'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for remand that I've seen before include "Send back into custody or bail" , "Keep in custody while waiting for trial" , "Commital to custody" , "Legally restrain" , "Return (often) to custody" .)