The word "参赛" is formed by combining two independent characters, each with its own meaning, to create a new, specific concept. The first character, "参" (cān), carries the core idea of "joining in" or "participating". The second character, "赛" (sài), contributes the notion of a "contest" or "competition". By fusing them, the compound directly and logically conveys the single action of "entering a competition" or "taking part in a contest", where the first character describes the action applied to the object named by the second.