Maybe Russian in bar almost drinking litre (4)
I believe the answer is:
slav
'maybe russian' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'in bar almost drinking litre' is the wordplay.
'in' is an insertion indicator.
'bar' becomes 'save' (both can mean 'except').
'almost' means to remove the last letter (most of the word but not all of it).
'drinking litre' becomes 'l' (I can't justify this - if you can you should believe this answer much more).
'save' with its last letter removed is 'sav'.
'sav' enclosing 'l' is 'SLAV'.
Can you help me to learn more?
(Other definitions for slav that I've seen before include "One of the European people" , "Native of eastern Europe, perhaps" , "One coming from Eastern Europe or Asian Russia" , "East European - Asian Russian" , "A Russian, say" .)