Lounge about with one fizzy drink, sweet (8)
I believe the answer is:
lollipop
'sweet' is the definition.
(lollipop is a kind of sweet)
'lounge about with one fizzy drink' is the wordplay.
'lounge about' becomes 'loll' (synonyms).
'with' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'fizzy drink' becomes 'pop' (pop is a type of fizzy drink).
'loll'+'i'+'pop'='LOLLIPOP'
(Other definitions for lollipop that I've seen before include "Confectionery" , "children love it" , "Boiled sweet" , "Sweet for suckers?" , "Sweet on a stick" .)