Nurse, as a cocktail (3)
I believe the answer is:
sip
'nurse as a cocktail' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sip that I've seen before include "Tiny amount of drink" , "Drink daintily" , "Drink gingerly" , "Drink slowly" , "Take in slowly" .)