An eye for a drink? (5)
I believe the answer is:
optic
This clue could be a double definition.
'an eye' is the first definition.
(I know that eye can be written as optic)
'drink?' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'for a' is the link.
Can you help me to learn more?
(Other definitions for optic that I've seen before include "Relating to the eyes" , "bar assistant" , "Of sight or the eye" , "Spirits measurer" , "Device for dispensing measures of spirits" .)