背骨 — meaning in English

bèi gǔ

English meaning

backbone noun The column of connected vertebrae running down the back that protects the spinal cord.
spine noun The column of bones running down the back, from the head down to the tail or pelvis, that protects the spinal cord and holds up the chest and abdomen.

背骨 is used for these senses in English:

backbone (countable) The series of vertebrae, separated by disks, that encloses and protects the spinal cord, and runs down the middle of the back in vertebrate animals.
spine (figurative) Courage or assertiveness.

noun The column of connected vertebrae running down the back that protects the spinal cord.
noun The essential support or core structure of a system or organization.
noun Firmness of character; courage.

noun The column of bones running down the back, from the head down to the tail or pelvis, that protects the spinal cord and holds up the chest and abdomen.
noun Bravery or a willingness to stand up for yourself.
noun A ridge or other long central structure that other parts branch out from, shaped a bit like a backbone.
noun The narrow edge of a book that holds the pages together and faces outward on a shelf, usually printed with the title and author's name.