Zeitoper is a German word that means "time opera" in English. However, there are several synonyms for this word, including time-operetta, temporal opera, clock opera, and duration opera. Other similar terms include chronoperetta, clockwork opera, timepiece opera, and temporal music drama. All of these synonyms refer to operas or musical performances that explore the concept of time and its passage. These operas often include themes of nostalgia, loss, and the fleeting nature of existence. Whether it's called a Zeitoper or any of its synonyms, this type of performance art seeks to understand the nature of time and how it affects human experience.