The adjective "stunning" has several meanings, but generally it refers to something that is very impressive or attractive. It can be used to describe a person who is physically beautiful or striking, with an appearance that takes one's breath away. The word can also refer to something that is amazing, surprising, or overwhelming in its impact - for example, "a stunning victory" or "stunning scenery." In some contexts, it may imply a sense of shock or disbelief, as when someone says "that's just stunning!" to express their surprise at something.