1. 不祥的；恶兆的；不吉利的
If you describe something as ominous, you mean that it worries you because it makes you think that something unpleasant is going to happen.

ominously
The bar seemed ominously quiet...
酒吧里非常安静，给人一种不祥的预感。
Ominously, car sales slumped in August...
8月份的汽车销量暴跌，这可不是个好兆头。
He spoke ominously of the world facing 'a war in Europe and possibly something greater'.
他作出不祥的预言，说世界将面临“一场发生在欧洲、甚至可能更大范围的战争”。