Momentary drink (5)
I believe the answer is:
short
I believe this clue is a double definition.
'momentary' is the first definition.
('short' can be similar in meaning to 'momentary')
'drink' is the second definition.
(Other definitions for short that I've seen before include "Having little length" , "Wanting" , "Uncivil, brief film" , "Curt" , "Neat" .)