I haven't been able to quit smoking completely, but at least I've cut down. [=cut back]我还不能完全把烟戒掉，但起码现在抽得少了。

I've had to cut down on [=reduce, cut back on] the amount of money I spend on clothes.我已不得不削减买衣服的开支。

She suggested he cut down on his drinking.她建议他少喝酒。

a building material that helps cut down on noise有助于降低噪声的建筑材料

Most of the tree was dead, so we had to cut it down.这棵树枯死了一大半，所以我们只好砍掉它。

Much of the forest has been cut down for firewood.这片树林的很大一部分都被砍掉当柴火了。

We used a shortcut that cut down our traveling time by 15 minutes.我们抄近路，把行程时间缩短了15分钟。

The machine significantly cuts down the amount of work necessary to harvest crops.这台机器大大减少了收割庄稼所需要的工作量。

She was cut down by a stray bullet.她被一颗流弹击中身亡。

The composer Schubert was cut down in his prime by illness. [=he died because of illness when he was in his prime]作曲家舒伯特正值盛年就被疾病夺去了生命。