Perform drunkenly with a bit of a snigger (4)

I believe the answer is:
sing
'perform' is the definition.
(to perform a song)
'drunkenly with a bit of a snigger' is the wordplay.
'drunkenly' becomes 'ing' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'a bit of' indicates taking the first letters.
The first letter of 'snigger' is 's'.
'ing' put after 's' is 'SING'.
Can you help me to learn more?
(Other definitions for sing that I've seen before include "behave like noisy tits" , "Turn informer" , "Celebrate" , "Make melodious sounds with voice" , "Inform - carol" .)
