The term "after-piece" refers to a theatrical performance that takes place after the main play or production. However, if we were to consider antonyms for this word, we could look at words that describe events that occur before or during the main performance. For instance, opening act, prelude, or introduction could be antonyms for after-piece. Similarly, if we were to consider antonyms that describe events that occur after the main show, we could use words such as epilogue, conclusion, or final curtain call. These antonyms offer us a range of options when discussing the parts of a theatrical production that occur before or after the main event.