Drink, drink! Time to swallow volume (8)
I believe the answer is:
beverage
'drink' is the definition.
('beverage' can be a synonym of 'drink')
'drink time to swallow volume' is the wordplay.
'drink' becomes 'beer' (beer is a kind of drink**).
'time' becomes 'age' (age is a kind of time).
'to swallow' is an insertion indicator.
'volume' becomes 'v'.
'beer'+'age'='beerage'
'beerage' placed around 'v' is 'BEVERAGE'.
(Other definitions for beverage that I've seen before include "Non-alcoholic drink" , "such as a Frappuccino" , "Liquid refreshment" , "Drink other than water" , "Prepared drink" .)