Play boisterously in maelstrom perhaps (4)
I believe the answer is:
romp
'play boisterously' is the definition.
(I've seen this in another clue)
'in maelstrom perhaps' is the wordplay.
'in' indicates a hidden word.
'ROMP' is hidden within 'maelstrom perhaps'.
(Other definitions for romp that I've seen before include "Boisterous prank" , "Energetic play" , "Frisk - gambol" , "Dance" , "Play in a lively way, like children" .)