What is the definition of relationship?

n.（名词）
1.The condition or fact of being related; connection or association.
关系：有关系的事实或状态；联系或关联
2.Connection by blood or marriage; kinship.
亲属关系：因血缘或婚姻产生的联系；亲戚关系
3.A particular type of connection existing between people related to or having dealings with each other:
联系：相互有来往的人之间存在的关联的特殊类型：
has a close relationship with his siblings.
和他的兄弟姐妹有紧密的联系
4.A romantic or sexual involvement.
浪漫关系或性关系