Number, few swirl in dance (9,4)
I believe the answer is:
eightsome reel
'dance' is the definition.
(I've seen this before)
'number few swirl in' is the wordplay.
'number' becomes 'eight' (eight is a kind of whole number).
'few' becomes 'some' (associated in meaning).
'swirl in' becomes 'reel' (I can't justify this - if you can you should believe this answer much more).
'eight'+'some'+'reel'='EIGHTSOME REEL'
Can you help me to learn more?
(Other definitions for eightsome reel that I've seen before include "See leg hit more (anag) - Scottish dance" , "Part of ceilidh perhaps" , "Lively Scottish dance" , "feature of ceilidh" .)