radiant
adj.adj. shining brightly or showing great happiness and health. You use it to describe a person's face when they are very happy or a light that is very strong.
adj. emitting light or heat; showing great joy, love, or health through a glowing appearance. Often used predicatively after 'look' or 'seem' to describe a person's expression.
The bride looked radiant as she walked down the aisle.
The morning sun cast a radiant light across the valley, waking the sleeping village.
Her radiant smile immediately put the nervous interviewees at ease, transforming the sterile office into a space of warmth and genuine connection.
From Middle English radyant, from Latin radiāns, radiantis, present participle of radiāre (“to emit rays or beams”).
Typically used to describe light sources or human expressions; often modified by 'absolutely' or 'truly'.