Nighthawks – possibly a right pair – drink beer – bottoms up! (7)
I believe the answer is:
artwork
'beer bottoms up' is the definition.
I can't judge whether this defines the answer.
'nighthawks possibly a right pair drink' is the wordplay.
'nighthawks possibly' becomes 'ark' (I can't explain this - if you can you should believe this answer much more).
'a right' becomes 'r' (common abbreviation).
'pair' becomes 'two' (a pair means two of something).
'drink' means one lot of letters goes inside another.
'r'+'two'='rtwo'
'ark' enclosing 'rtwo' is 'ARTWORK'.
Can you help me to learn more?
(Other definitions for artwork that I've seen before include "Graphics" , "Painting" , "Illustrative material in publication" , "Illustrations in book" , "Illustrations and designs for printing" .)