Swimmer having a bit of fun in ballet (5)
I believe the answer is:
dance
'ballet' is the definition.
(I've seen this in another clue)
'swimmer having a bit of fun' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'in' acts as a link.
Can you help me to learn more?
(Other definitions for dance that I've seen before include "Eg, waltz, foxtrot" , "Ball; hop" , "Quickstep, e.g." , "Eg, perform ballet" , "social event" .)