Songwriter Sondheim (7)
I believe the answer is:
stephen
'songwriter sondheim' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stephen that I've seen before include "Male" , "First Christian martyr" , "Old king" , "-- Hawking (A Brief History of Time)" , "Author of The Shining" .)