名詞 downhill:

1. the downward slope of a hill
2. a ski race down a trail

形容詞 downhill:

1. sloping down rather steeply
   同義詞：declivitous, downward-sloping

副詞 downhill:

1. toward a lower or inferior state
2. toward the bottom of a hill

1. Luckily, the car was facing downhill when it broke down, and we were able so shove it home.
   幸運的是，車拋錨的時候是面向下山方向的，我們能將它推回家。
2. Business is going downhill.
   生意正走下坡。

down.hill

adv.（副詞）
Down the slope of a hill.
向山下
Toward a lower or worse condition:
如下坡一般：走向下坡或更壞的條件：
例句：
The alcoholic`s health went downhill fast.
嗜酒者的健康狀況迅速下降

adj.（形容詞）

Sloping downward; descending.
向下的；下降的
Sports Of, relating to, or constituting skiing down a slope:
【體育運動】 滑降的：下降滑雪的：
例句：
a downhill racer.
快速下降的滑雪運動員

n.（名詞）
A downhill skiing race.
滑降比賽
A downward gradient; a descending slope.
下坡；斜坡