First performance (5)
'first performance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for debut that I've seen before include "First attempt" , "First appearance, coming out" , "Beginning, first performance" , "where one began" , "Aurora" .)
'first performance' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for premiere that I've seen before include "First showing of play or film" , "Leading actress" , "Opening night" , "First screening" , "Leading lady" .)