1 [C] the row of small bones that are connected together down the middle of your back 脊柱；脊梁 [SYN] spine 同义词为 spine ☞picture at body 见body插图

2 [sing] the most important part of sth 支柱；最重要的部份: Agriculture is the backbone of the country's economy. 农业是该国经济的支柱。