Fish not a single person wanted after drink (7)
I believe the answer is:
alewife
'fish' is the definition.
(I know that alewife is a type of fish)
'wanted after drink' is the wordplay.
'wanted' becomes 'wife' (I can't explain this - if you can you should believe this answer much more).
'after' says to put letters next to each other.
'drink' becomes 'ale' (type of beer).
'wife' put after 'ale' is 'ALEWIFE'.
'not a single person' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for alewife that I've seen before include "serving fish" , "superior, > swimmer found" , "a catch" .)