The word "日常" is formed through a direct and logical conceptual combination of its two component characters: "日", which means "sun" or "day", and "常", which means "constant", "regular", or "ordinary". It is not a metaphorical or abstract pairing, but rather a literal fusion where "常" (constant) describes and qualifies the nature of "日" (day), effectively creating the core meaning of "daily constancy" or "day-to-day regularity". This formation immediately evokes the inherent, repeating routines and ordinary matters that fill the span of a day.