The column of bones in the back which sustains and gives firmness to the frame; the spine; the vertebral or spinal column.
- The vertebrate spine or spinal column.
- Something, such as the keel of a ship, that resembles a backbone.
- A main support or major sustaining factor: the backbone of a thesis.
- Geology A ridge forming the principal axis of a mountain.
- Geology The principal mountain ridge, range, or system of a region.
- Chemistry The main chain of atoms in a polymer.
- Strength of character; determination: displayed grit and backbone in facing adversity.