Espresso + milk (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
latte
(Other definitions for latte that I've seen before include "Espresso added to frothed steamed milk" , "See 21" , "Espresso with frothy milk" , "Coffee with a topping of frothed steamed milk" , "Italian word for milk" .)