1. impossible to climb or scale
2. unable to be expanded or increased in size, capacity, or scope
Usage: computing; business

Examples

• The fortress was built on an unscalable cliff face.
• The mountain’s sheer walls appeared completely unscalable.
• Their current software architecture is unscalable for large user bases.
• The company’s unscalable business model limited its growth potential.
• Rock climbers considered the vertical granite wall unscalable without equipment.
• The startup’s unscalable operations became a problem as demand increased.