这些词都有好多意思的,也有好多词性,不知道你要哪个……只好挑最常用的了：
1.[countable] an agreement or arrangement,especially in business or politics,that helps both sides involved.
2.used to say that something will happen or be true if something else does not happen or is not true.
3.not right or fair,especially because not everyone has an equal opportunity.
4.to do something that produces an effect or change in something or in someone’s situation.
5.to find or provide a way of dealing with a problem.
6.something that tests strength,skill,or ability,especially in a way that is interesting.
7.attention or consideration that is shown towards someone or something.
8.intelligent or sensible.
9.something that you have to do because it is morally or legally right.
10.used to say what is not used,does not happen etc,when something else is used,happens etc.
摘自《朗文当代高级英语词典》（第五版）,权威词条.
