Wan is an adjective that means pale or light in complexion.
Coming from Old English, our word of the day’s origin is something of a mystery. But we do know it is something of a synonym of words like pallid or ashen. Example:
Having a wan complexion can often make people not seem healthy. But in Steve’s case, his pale skin has nothing to do with being ill. He’s just the product of very light-complected people.