Crowds having a bit of fun during May (4)

I believe the answer is:
many
'crowds having a bit' is the definition.
I can't tell whether this defines the answer.
'fun during may' is the wordplay.
'fun' becomes 'n' (I can't explain this - if you can you should believe this answer much more).
'during' indicates putting letters inside.
'n' inserted inside 'may' is 'MANY'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for many that I've seen before include "multitude" , "Several" , "regarded as a large number" , "Numerous" , "Multitudinous" .)
