The crossword solution for the term 'Mephisto Waltz Star' is ALDA, which is the surname of the American actress and singer, Celeste Holm. She is best known for her role as Ado Annie in the 1955 film adaptation of Rodgers and Hammerstein's musical Oklahoma!, as well as her Academy Award-winning performance in Gentleman's Agreement. She also starred in the 1971 horror film The Mephisto Waltz, playing the role of Myra Breckinridge.