The word "今晚" is formed by directly combining two individual characters: "今", which means "now" or "today", and "晚", which means "evening" or "night". This construction follows a common pattern in Chinese where discrete meaning units are merged to create a new, composite concept, here, specifying the evening of the current day, effectively conveying "tonight". The formation relies on the semantic contribution of each character, where "今" anchors the time to the present and "晚" defines the period, resulting in a clear, concise temporal reference without need for additional grammatical markers.