1. a solid foundation laid below ground level to support or strengthen a building
Usage: construction; architecture
2. a set of ideas, principles, or facts that form the basis or foundation for something
Usage: figurative

Examples

• The old building required new underpinning to prevent it from collapsing.
• Engineers examined the concrete underpinning of the bridge.
• The underpinning of democracy is the right to vote.
• Scientific research forms the underpinning of modern medicine.
• The theory lacks solid underpinning in empirical evidence.
• Economic stability provides the underpinning for social progress.
• The underpinning of the structure was damaged by the earthquake.