1. (人、团体或国家之间的)联系，关系，往来
    Relations between people, groups, or countries are contacts between them and the way in which they behave towards each other.

relation

    e.g. Greece has established full diplomatic relations with Israel...
           希腊已经和以色列建立了全面的外交关系。
    e.g. Apparently relations between husband and wife had not improved...
           很明显夫妇之间的关系没有改善。

2. (两者之间的)关系，联系，关联
    If you talk about the relation of one thing to another, you are talking about the ways in which they are connected.

    e.g. It is a question of the relation of ethics to economics.
           这是一个伦理学和经济学的关系问题。
    e.g. ...a relation between youthful unemployment and drug-related offences...
           年轻人失业与毒品相关犯罪之间的关联

3. 亲戚;亲属;家庭成员
    Your relations are the members of your family.

    e.g. ...visits to friends and relations...
           拜访亲友
    e.g. In America they are touting Hugh Grant as the next Cary Grant (no relation).
           在美国，他们把休·格兰特吹捧为第二个加里·格兰特(两人并无亲属关系)。

4. 与…相比
    You can talk about something in relation to something else when you want to compare the size, condition, or position of the two things.

    e.g. The money he'd been ordered to pay was minimal in relation to his salary.
           他被要求支付的金额与他的薪水相比微不足道。
    e.g. ...women's position in relation to men in the context of the family...
           在家庭范围内女人相对于男人的位置

5. 关于;涉及
    If something is said or done in relation to a subject, it is said or done in connection with that subject.

    e.g. ...a question which has been asked many times in relation to Irish affairs...
           被问过多次的关于爱尔兰事务的问题
    e.g. He is the sixth person to be arrested in relation to the coup plot.
           他是政变阴谋牵涉到的第6个被捕的人。