The word 终生 is formed by combining two meaningful characters: 终, which means "end" or "through to the end", and 生, which means "life" or "to be born". Their formation is purely ideographic and conceptual, where the first character 终 modifies and frames the second character 生. Together, they create a single, fused concept that visually and semantically represents the span of "from the beginning to the end of a lifetime", effectively picturing the entirety of one's life as a complete journey from birth to its conclusion.