The word "今夜" is formed by the direct, conceptual combination of two independent characters: "今", which represents the idea of "the present" or "this", and "夜", which embodies the concept of "night". It is a straightforward semantic fusion where the first element specifies the temporal frame ("this") and the second element provides the substantive subject ("night"), creating a new, single unit of meaning that points specifically to the night occurring within the current cycle of time.