Case in which bottles may be locked with their contents visible (8)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
tantalus
(Other definitions for tantalus that I've seen before include "Lydian king" , "Frustrated Greek" , "Lockable case for decanters" , "Son of Zeus and case for decanters" , "ancient king" .)