The word "焕然一新" is formed by combining "焕然", meaning "brightly" or "glowingly", with "一新", meaning "completely new". The character "焕" conveys brightness, "然" functions as an adverbial suffix, "一" emphasizes entirety, and "新" denotes newness, together creating a compound idiom that literally describes something becoming bright and entirely new, indicating a thorough renewal.