Last letters by medic are entirely about dairy product (10)
I believe the answer is:
mozzarella
'dairy product' is the definition.
(mozzarella is a kind of dairy product)
'last letters by medic are entirely about' is the wordplay.
I cannot quite understand how this works, but
'medic' could be 'mo' (medical officer) and 'mo' is found in the answer.
'are' could be 'a' (the 'are' is a metric unit of area) and 'a' is found within the answer.
'about' could be 're' (common abbreviation for 'with reference to') and 're' is present in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for mozzarella that I've seen before include "Dairy product, originally from buffaloes" , "Buffalo milk cheese" , "White Italian cheese" .)