Carton's inside around five wanting a bit of tea - that's Sydney's afternoon! (4)
I believe the answer is:
arvo
'five wanting a bit of tea that's sydney's afternoon' is the definition.
I can't tell whether this defines the answer.
'carton's inside around' is the wordplay.
'carton's inside' becomes 'arv' (I am not sure about this - if you are sure you should believe this answer much more).
'around' becomes 'o' (I've seen this in other clues).
'arv'+'o'='ARVO'
Can you help me to learn more?
(Other definitions for arvo that I've seen before include "PM (Aus.); --- Part, composer" , "afternoon in Sydney" , "PM in Canberra" , "Aussie PM" , "Australian PM" .)