Once more, a drink around midday (5)
I believe the answer is:
again
'once more' is the definition.
(synonyms)
'a drink around midday' is the wordplay.
'drink around' becomes 'gai' (I can't explain this - if you can you should give a lot more credence to this answer).
'midday' becomes 'n' (abbreviation for noon).
'a'+'gai'+'n'='AGAIN'
Can you help me to learn more?
(Other definitions for again that I've seen before include "One more time, encore" , "Here we go ___" , "Ocne more" , "'Another time, once more (5)'" , "Repeatedly" .)