The word "radiant" describes something that emits light or brightness, often conveying a sense of warmth, joy, or beauty. It is commonly used to refer to a person's appearance or demeanor when they seem particularly happy or glowing. A radiant smile, for example, might be one that is bright and full of warmth, lighting up the face.
The word "radiant" comes from the Latin root "radiant-" meaning "shining" or "emitting rays". This is derived from "radiare," which means "to emit rays" and is related to "radius," indicating a ray or beam of light. It has been used in English since the 15th century.