Unappealing means not attractive and not pleasant — something you do not feel drawn to. It covers a wide range: food, places, jobs, offers, ideas, people's behaviour. 'An unappealing flat', 'an unappealing job offer', 'His attitude is deeply unappealing.' The important thing about this word is its politeness level. It is softer and more polite than ugly, horrible or disgusting, because it says how something affects YOU rather than declaring what it IS. That makes it very useful when you want to turn something down without being harsh: 'The idea is unappealing to me' is much gentler than 'That's a terrible idea.' British speakers especially use it this way, as understated criticism. It often appears with 'to' plus a person: 'unappealing to younger customers'. It also takes strong modifiers happily: distinctly unappealing, thoroughly unappealing, singularly unappealing — and those combinations can be quite cutting even though every single word is polite. Note it does not mean 'boring'. A thing can be exciting and still unappealing — a dangerous job, for instance.

不吸引人的、讓人提不起興趣的。台灣口語裡接近「沒什麼吸引力」「讓人不太想碰」，語氣比「難看」「噁心」客氣很多