1. the quality or state of being hard; firmness or solidity
2. difficulty or severity of conditions or circumstances
3. the resistance of a material to scratching, cutting, or penetration
Usage: technical

Examples

• The hardnesses of different metals vary significantly.
• Engineers test the hardnesses of materials before construction.
• The hardnesses of winter made travel difficult.
• She endured the hardnesses of pioneer life.
• The diamond’s hardness makes it valuable for cutting tools.
• Different steel alloys have different hardnesses.
• The hardnesses they faced only made them stronger.