应该是

failed[feild]

动词fail的过去式

adj. 失败的, 不成熟的

例句：

1.If it had not been for his help, I should have failed.

如果没有他的帮忙，我应该已经失败。

2.But for your advice, I should have failed.

要不是你的忠告，我会失败的。

3.Blood can be cleaned by osmosis if the kidneys have failed.

若肾功能衰退，可通过渗透作用使血液净化。

4.The government's repression of the strike failed.

政府对这次罢工的镇压失败了。

5.His speech failed in proof.

他的演讲缺乏证据。

6.Their business has failed and is in the hands of the receiver.

他们的公司垮了，现在由破产管理人管理。

7.The business faltered and then failed.

商行生意衰退，最后倒闭了。

8.I tried to fix the equipment but I failed.

我想把机器修理好，但是失败了。