Vodka doses up pint-sized soft drink (4)
I believe the answer is:
soda
'soft drink' is the definition.
(I know that soft drink can be written as soda)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for soda that I've seen before include "Mixer drink" , "Drink containing carbonated water and sometimes flavouring" , ""Splashed" drinks mixer" , "fizz" , "pressurised liquid" .)