Making a comeback, lives on energy drink (5)

'drink' is the definition.
(Pepsi is an example)

'making a comeback lives on energy' is the wordplay.
'making a comeback' shows that the letters should be reversed in order.
'lives' becomes 'is' ('be' can be a synonym of 'live').
'on' means one lot of letters go next to another.
'energy' becomes 'pep' (personal energy, vim).
'is'+'pep'='ispep'
'ispep' backwards is 'PEPSI'.