Swim round and round? (4)
I believe the answer is:
reel
I believe this clue is a triple definition!
'swim' is the first definition.
(I've seen this before)
'round' is the second definition.
(thesaurus)
'and' is a link.
'round?' is the third definition.
(thesaurus)
(Other definitions for reel that I've seen before include "Stagger with rod winder" , "wind-up?" , "Lively dance or fishing rod controller" , "Part of film; dance" , "Folk dance" .)