The crossword solutions for the term FALSTAFF or 'FIDELIO' is OPERA. Falstaff is an OPERA in three acts by Giuseppe Verdi, based on Shakespeare's The Merry Wives of Windsor. Fidelio is a German OPERA with music by Ludwig van Beethoven and a libretto by Joseph Sonnleithner, Georg Friedrich Treitschke, and Stephan von Breuning. Both operas are examples of the genre of OPERA, which is a form of musical theatre that combines singing, spoken dialogue, and acting.