Someone who is strikingly beautiful can be described as stunning. There's something magical about weddings that makes every bride look stunning.
The adjective stunning also means causing astonishment, shock, or disbelief. If your basketball team suffers a stunning defeat, it comes at the hands of a rival team you were positive you would beat. Stunning is rooted in the Old French verb estoner, meaning to stun or shock, and it was used in the 1800s as a synonym for excellent. It's still used this way, particularly when something is really impressive, like the school mime troupe's stunning performance.