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 the answer is hidden within the clue.
'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" .)