12 across
Cold
musician’s
unlimited
drink
(6)
Cold musician’s unlimited drink (6)
hints
0
checks
0
hints
The definition is at the end of the clue.
How the clue works
The definition is drink — cassis being that blackcurrant liqueur. "Cold" hands you C, then "musician's unlimited" takes BASSIST and strips its outer letters, leaving ASSIS. Put C in front of ASSIS and you're done.