"Final curtains" is an idiomatic expression that refers to the ending of an event, performance, or even someone's life. A few synonyms that could be used in place of this phrase include "last act," "final chapter," "ultimate closure," "ultimate end," or simply "conclusion." Other options could include "final bow," "last hurrah," "ultimate goodbye," or "final curtain call." Each of these phrases implies a sense of finality and closure, often indicating that something has come to an end or reached its inevitable conclusion. Whether used in the context of an artistic performance or as a metaphor for passing away, these synonyms all convey the idea of an ultimate ending.