Composer of the opera "Lohengrin" (6)
I believe the answer is:
wagner
(Other definitions for wagner that I've seen before include "German opera composer" , "Richard . . . . . . composer of 'The Flying Dutchman' and 'Lohengrin'" , "Composer honoured in Bayreuth" , "Composer of ''The Flying Dutchman'' etc" , "Tannhauser composer" .)