He's a bit of a dancer (3)
I believe the answer is:
dan
'bit of a dancer' is the definition.
The definition suggests a singular noun which matches the answer.
'he's a' is the wordplay.
'he's' becomes 'd' (I can't explain this - if you can you should give a lot more credence to this answer).
'a' becomes 'an'.
'd'+'an'='DAN'
Can you help me to learn more?
(Other definitions for dan that I've seen before include "Level of competence in judo" , "Expertise level in juso" , "Grade of proficiency in judo" , "-- Dare, comic hero" , "Jacob's fourth son" .)