If the door's not closed, you can get a drink (4)
I believe the answer is:
ajar
'if the door's not closed you' is the definition.
I can't judge whether this definition defines the answer.
'get a drink' is the wordplay.
'get' is a charade indicator (letters next to each other).
'drink' becomes 'jar' (colloquial).
'a' put next to 'jar' is 'AJAR'.
'can' acts as a link.
Can you help me to learn more?
(Other definitions for ajar that I've seen before include "Partly open" , "near closing?" , "A litle bit open" , "Half open" , "Partially open" .)