What does “ti naeda” mean in Korean?

티 is the giveaway: the mark a mood, a habit or a background leaves on a person. 티 내다 is letting that show, on purpose or by accident, and 티 나다 is it showing by itself. 티 안 나게 하다 means doing something so nobody can tell. This is the vocabulary of feelings you were trying to keep off your face.

In the clip a girlfriend teases her boyfriend for seeming so unbothered: 티를 안 내려고 많이 했지? — “you were working hard not to let it show, weren’t you?” The word attaches to types as well as moods: 학생 티가 난다 (“you can tell she’s a student”), 촌티 for a countrified look, 초보 티 for an obvious beginner.