Working in musical returning to entertain city's West End (6)
I believe the answer is:
active
'working' is the definition.
(similar in meaning)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for active that I've seen before include "Not passive" , "Busy, not idle" , "In actual operation" , "Lively, working away" , "Dynamic, functioning" .)