Second drink is a coffee? (5)
I believe the answer is:
mocha
'coffee?' is the definition.
(type of coffee drink)
'second drink' is the wordplay.
'second' becomes 'mo' (both are short periods of time).
'drink' becomes 'cha' (cha can mean tea).
'mo'+'cha'='MOCHA'
'is a' is the link.
(Other definitions for mocha that I've seen before include "Arabian coffee" , "Kid" , "Yemeni port; type of coffee bean" , "Coffee flavour" , "Dark brown" .)