Cavort like a fathead, perchance? (5)
I believe the answer is:
frisk
'cavort' is the definition.
('frisk' can be a synonym of 'cavort')
'a fathead perchance?' is the wordplay.
'a fathead' becomes 'f' (head letter of 'fat').
'perchance?' becomes 'risk' (I can't explain this - if you can you should believe this answer much more).
'f'+'risk'='FRISK'
'like' is the link.
Can you help me to learn more?
(Other definitions for frisk that I've seen before include "body check" , "Skip playfully, frolic" , "Body search for concealed weapons or drugs" , "Gambol" , "Search someone by feeling" .)