n.

1. 脊骨，脊柱[C]
2. 主（山）脉，干脉
3. 支柱；骨干；基础[the S]
   Agriculture used to be the economic backbone of this country.

   农业曾是这个国家的经济支柱。

4. 骨气；坚毅，毅力[U]
   Standing up to bullies takes plenty of backbone.

   勇敢地对付暴徒需有大无畏精神。

n.

1. the spine.
2. the chief support of a system or organization.
   ▸strength of character.
3. Computing  & Telecommunications  a high-speed, high-capacity digital connection which forms the axis of a local or wide area network.