noun
Derogatory term for an unattractive woman. Strongly insulting; avoid in polite conversation.
あのブス、また遅刻かよ。
That ugly woman is late again.
ブスって言うな！
Don't call me ugly!
na-adjective, noun
Colloquial and derogatory adjective meaning ugly, often used for people but can apply to things. ブスな/ブスだ pattern.
その服、ちょっとブスじゃない？
Isn't that outfit a bit ugly?
ブスな顔してごめんね。
Sorry for having an ugly face.
The origin is uncertain. Possibly derived from the verb ぶす (to fester) or from 不図 (busu) meaning 'absent-mindedly', but the connection is unclear. The katakana spelling ブス is standard in modern slang.