1. the series of connected bones down the middle of the back; spines
Usage: anatomy
2. the most important parts of systems or organizations; main supports
Usage: figurative
3. people who show strength and determination; those with courage
Usage: figurative

Examples

• The X-rays showed fractures in two of the patient’s backbones.
• Small businesses are the backbones of many local economies.
• The volunteers became the backbones of the relief effort.
• These dedicated teachers are the backbones of our school system.
• The injury affected several vertebrae in their backbones.
• Without these key employees, who are the backbones of the company, we couldn’t succeed.