Take a small drink (3)
I believe the answer is:
sip
'take a small drink' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sip that I've seen before include "Drink slowly" , "Take a little of a drink" , "Drink daintily" , "Take small mouthfuls of (drink)" , "Drink gingerly" .)