Do you mean what is handsome in Korean? It is 잘생겼다. Or "handsome guy" could be translated as 미남. ex. 저 남자 미남이네. (He is a handsome guy.)

Hi, Wendy. One of my italki friends just asked the same question, which I answered at length in the top two comments of this discussion: https://www.italki.com/discussion/246838