It's not "ブセ" but "グセ (guse)". We describe this word "癖" in kanji. The most similar word in English is "habit", maybe. 1.寝グセ　is "bed hair". We use 癖 in this word as our hair has habit of curve as it is when we are sleeping. 2.遅刻グセ　is "lateness" It means someone's habit of lateness.

joh-eun achim dangsin-eun eotteohge chingu