The word "旧事" (jiùshì) is a compound noun formed through a straightforward semantic combination of its two constituent characters: "旧" meaning "old," "former," or "past," and "事" meaning "matter," "affair," or "event." It follows the common Chinese word-formation structure of a modifier ("旧") describing the head noun ("事"), resulting in the meaning "past events" or "bygones." This formation is analogous to English compound nouns like "backstory" or "history," where the first element specifies the temporal quality of the second, creating a single, cohesive concept often used in literary or reflective contexts to denote memories or historical incidents.