The word "一生" is formed through the direct and conceptual combination of two fundamental characters: "一" (yī), meaning "one" or "single", and "生" (shēng), meaning "life" or "birth". They are joined not by grammar, but by a figurative, almost pictorial logic where "one" modifies "life" to create the immediate image of a single, complete lifespan, a unified journey from birth to death, encapsulating the entirety of one's existence in a single, enduring unit of time.