The word 终身 is formed through the conceptual combination of its two component characters: 终, which carries the meaning of "end", "conclusion", or the "entirety" of a process, and 身, which means "body" or "one's person". Together, they create a metaphorical image meaning "to the end of one's body" or "for the entire length of one's physical existence", thus directly and visually conveying the idea of "lifetime" or "lifelong".