如果大家经常看体育比赛，可能会时不时听见“foul”这个词。在体育英语中，“foul”的意思是“犯规”。而在日常生活中，“foul”这个词使用的频率也很高，使用的场合大多数也和“犯规”有关。
在《经济学人》（The Economist）的一篇文章中，有这样一句话：
Dozens official party bosses have fallen foul of a national anti-bribery campaign.
“anti-bribery”就是“反贿赂”，“fall”表示“落下”。结合句中“党派”的背景，很容易猜想“fall foul of”可能和“落马”有关。
查了词典之后，发现确实如此。“fall foul of”的意思为“to get into a situation where one is opposed to someone or something; to get into trouble with someone or something; to break a law or a rule, and often be punished”。这样看来，正是中文中的“冲突，触犯，惹麻烦，落马”。
其实，“foul”既可以作名词，也可以作动词。作动词时，“foul”的意思是“弄脏”。英语中有一个谚语就和这种意思有关：
It's an ill bird that fouls its own nest。
我们常说“笨鸟先飞”，因为如果不飞，笨鸟可能会弄坏自己的巢。这种害群之鸟，还是快点飞走为好。
如果将上面那句谚语引申一下，我们可以这样解释它：Only a foolish or dishonorable person would bring dishonor to his or her self or his or her surroundings。或者，我们可以说：Only a bad person would ruin the place where he or she lives.
我们来看一个具体的例子：
I don't like my new neighbor. Not only does he never mow his lawn, he covers it with all kinds of trash. It's an ill bird that fouls its own nest.
例句中的那个人就是一个典型的“自毁家门”或“自取其辱”的人。
有时，我们也可以把上面那句谚语直接说成“foul one's own nest”，用来表达“自毁家门”或“自取其辱”的行为，即“to harm one's own interests; to bring disadvantage upon oneself”。
例如，She certainly fouled her own nest when she spread those rumors about him.
最后，“foul”还可以作形容词，表示“犯规的；邪恶的；下流的”。
英文中，经常用“foul-mouthed”来表示一个人“语言猥琐”或“说话下流”。如果一个人总是“foul-mouthed”，那么大概很少有人会愿意和他长期相处。正如下面这个例句中的女孩：
I don't want to see that foul-mouthed girl play with our kids ever again—she taught them curse words.
