hardness
The quality of being rigid or resistant to pressure and scratching. / The state of being difficult to understand, deal with, or endure. / The mineral content of water, specifically calcium and magnesium ions.
[C/U] Both
This term evokes a sensation of unyielding resistance. In a material sense, it suggests a surface that cannot be indented or scratched, creating an image of permanence and strength. It is the primary descriptor for durability in geology and engineering.
When applied to human emotion or life circumstances, it shifts toward a cold, austere, or merciless quality. It describes a lack of empathy or a grueling environment that strips away softness and vulnerability, often carrying a negative or oppressive connotation.
Uncountable when describing the physical property of a material or the emotional state of a person. Countable when referring to specific measured levels of mineral content in different water samples.