■ downhill

作为形容词或副词，原意是“走下坡路”。但是这个意义可以指“顺利”，也可以指“每况愈下”。

• It should all be downhill from now on.从今以后，会事事顺利。
• When you get to forty, it's downhill all the way.人到四十就一直走下坡路。
• It's a relationship that's been going downhill pretty much since 2002. (The Associated Press, Feb. 17, 2008)这个关系，自从 2002 年以来就一直走下坡路。

值得注意的是，反义词 uphill 只有“吃力”、“不顺利”的意义。