During the night, sound angry about a bit of fun! (5)
I believe the answer is:
snore
'during the night sound' is the definition.
(to snore is to make a sound at night)
'angry about a bit of fun' is the wordplay.
'angry' becomes 'sore' (similar in meaning).
'about' is an insertion indicator.
'a bit of fun' becomes 'n' (I am not sure about this - if you are sure you should believe this answer much more).
'sore' placed around 'n' is 'SNORE'.
Can you help me to learn more?
(Other definitions for snore that I've seen before include "Make raucous nasal sound during sleep" , "thing which bores" , "Noise indicating sleep" , "Breathe noisily during sleep" , "Noise made while asleep" .)