The word "完美无瑕" is formed by combining the two-character phrase "完美", meaning "perfect" (from "完" for complete and "美" for beautiful), with the two-character phrase "无瑕", meaning "flawless" (from "无" for without and "瑕" for flaw). This combination creates a compound term that intensifies the meaning of perfection by explicitly adding the notion of having no imperfections.