Medical man imprisoned for a harmless frolic (6)
I believe the answer is:
gambol
'harmless frolic' is the definition.
'gambol' can be an answer for 'frolic' (synonyms). I'm not sure about the 'harmless' bit.
'medical man imprisoned for a' is the wordplay.
'medical man' becomes 'MB' (someone with a Bachelor of Medicine degree).
'imprisoned' indicates putting letters inside.
'for a' becomes 'gaol' (I am not sure about this - if you are sure you should believe this answer much more).
'mb' put into 'gaol' is 'GAMBOL'.
Can you help me to learn more?
(Other definitions for gambol that I've seen before include "Caper and cavort (6)" , "jump for joy" , "Frisk, frolic" , "Prance; sounds like bet" , "Skip" .)