1 something that joins two or more people or groups of people together, such as a feeling of friendship 联系（起连结作用的事物，例如友谊）: Our two countries are united by bonds of friendship. 我们两国关系友好。

2 a certificate that you can buy from a government or company that promises to pay you interest on the money you have given 债券；公债

3 (technical术语) (in chemistry 化学) the way in which ATOMS are held together in a chemical compound 键