The word 夜间 (yèjiān) is a compound noun formed through the combination of two meaningful characters: 夜 (yè), which means "night", and 间 (jiān), which denotes a "period" or "interval of time". When combined, they create a single lexical unit that means "nighttime" or "during the night", where 间 specifies the temporal frame within which the state of 夜 occurs. This follows a common pattern in Chinese word formation where a concrete noun (夜) is modified by a more abstract noun (间) to create a new, specific time-related concept.