Follow-up drink for one making an impression (6)
I believe the answer is:
chaser
This might be a double definition.
'follow-up drink' is the first definition.
(I've seen this before)
'one making an impression' is the second definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for chaser that I've seen before include "Yellow-Dog Dingo?" , "Drink following another of a different kind" , "Racing horse" , "engraver" , "one in the national hunt" .)