Whiskey chaser and a penetrating look (1-3)
I believe the answer is:
x-ray
This clue might be a double definition.
'whiskey chaser' is the first definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'a penetrating look' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'and' acts as a link.
Can you help me to learn more?
(Other definitions for x-ray that I've seen before include "Medical image?" , "Hospital photo" , "Aid to medical investigation" , "Diagnostic picture" , "Rontgen's discovery" .)