A change in the way someone or something looks — but not a small change. It means the whole appearance is remade, usually into something more beautiful, brighter, or more glorious than before. If a tired old room becomes lovely under candlelight, or a shy student's face lights up completely when they talk about the thing they love, you can call it a transfiguration. The word is formal and literary, and it always carries a feeling of wonder — as if something inside has come out and shown itself on the surface. It also has a specific Christian meaning, usually written with a capital T: the Transfiguration is the moment in the Bible when Jesus goes up a mountain and his face and clothes shine with light in front of his disciples. Much of the word's grand feeling comes from that story, which is why even the everyday use sounds a little holy. Because the word is heavy, writers use it carefully; if you only mean someone changed clothes or got a haircut, the ordinary word is 'transformation' or 'makeover'.