Composer ____ Bernstein (7)
I believe the answer is:
leonard
'composer bernstein' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for leonard that I've seen before include "man" , "-- Cohen, singer" , "Fellow" , "Elmore ___ , US thriller writer, d. 2013" , "-- Bernstein, US conductor" .)