Admit when Rolf's taken in (5)
I believe the answer is:
enrol
'admit' is the definition.
The definition and answer can be both to do with social activities as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'when rolf's taken in' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ENROL' is hidden in the letters of 'when rolf taken'.
Can you help me to learn more?
(Other definitions for enrol that I've seen before include "register for classes" , "Join as member" , "Add to list of members" , "Insert in register" , "Join up, sing on" .)