Vegas casino with a musical name (4)
I believe the answer is:
aria
'vegas casino with a musical name' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aria that I've seen before include "Musical performance" , "Song for solo voice from an oratorio, cantata etc" , "Type of song" , "Operatic number" , "Operatic song" .)