Graduate in leather mixed drink (6,3)
I believe the answer is:
herbal tea
'drink' is the definition.
(herbal tea is a kind of drink)
'graduate in leather mixed' is the wordplay.
'graduate' becomes 'ba'.
'in' means one lot of letters goes inside another.
'mixed' indicates anagramming the letters.
'leather' with letters rearranged gives 'herltea'.
'ba' going into 'herltea' is 'HERBAL TEA'.
(Other definitions for herbal tea that I've seen before include "healthy drink" , "liquid concoction" , "hot drink" , "Plant infusion" .)