The idiom "民不聊生" is formed by directly combining four characters: "民" (people) as the subject, "不" (not) for negation, "聊" (to rely on) as the verb, and "生" (life/livelihood) as the object, resulting in the literal meaning "the people have nothing to rely on for life", expressing a condition of severe deprivation where basic sustenance is unattainable.