Doctor with a medium drink (4)
I believe the answer is:
dram
'drink' is the definition.
(small alcoholic drink)
'doctor with a medium' is the wordplay.
I cannot quite understand how this works, but
'doctor' could be 'dr' (abbreviation) and 'dr' is found within the answer.
'a' is within the answer.
'medium' could be 'm' (as in UK clothing sizes) and 'm' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dram that I've seen before include "A wee spirit" , "Wee drop of whisky?" , "Nip, snifter" , "Small drink (Scots)" , "Small drink of scotch" .)