now that I look at the popular slangs that people use nowadays, many of them were made by idols.
Shinhwa Shin Hyesung: 깜놀 (kkam-nol: startled/surprised, comes from 깜짝놀랐어),
갑툭튀 (kaptoktwi: out of the blue, comes from 갑자기 툭 튀어나온).
Shinhwa Junjin: 완전 ~하다 (wanjeon Xhada: it's totally X!)
Bigbang GD: 행쇼 (haengshyo: be happy)
Shinee Jonghyun: 뇌섹남/녀 (noeseknam/nyeo: man or woman with a sexy brain, comes from noe (brain)+sek (sexy))
EXO D.O: ㅇ젤ㅇ. ex세젤예. (X-jel-X, it's a bit hard to translate but "jel" means "the most", so "세젤예: Se-jel-ye" = "the prettiest (je-il yeppo) on earth (sesang)")
Infinite : ~이즈뭔들(is mwondeul: X is everything, mostly used among fandoms to describe their biases)
Btob Ilhoon: 귀요미송 (the gwiyomi song, even though it wasn't a slang, it's so famous!!)
Henry: 1도 모르겠다 (il-do moleugetta: I don't know what's going on, I don't know one bit)
btw, Happy new year!!
original post: here