Definition

1. Noun:
   • The quality of being rigid and resistant to pressure; not easily scratched: This is the physical property of a solid material that resists deformation, indentation, or penetration. It is often measured scientifically (e.g., on the Mohs scale for minerals).
   • The quality of being difficult to do or accomplish; difficulty: This refers to the challenging nature of a task, problem, or situation.
   • Excessive sternness; severity of character; hardheartedness: This describes a lack of compassion, sympathy, or gentleness in a person's nature or actions.
   • A quality of water that contains dissolved mineral salts (like calcium and magnesium) that prevent soap from lathering easily: This is a specific chemical property of water.

Usage Examples

• Physical Property:

  • The hardness of a diamond allows it to cut glass.
  • They tested the metal's hardness before using it in construction.

• Difficulty:

  • The hardness of the final exam surprised all the students.
  • We underestimated the hardness of the climb.

• Sternness of Character:

  • The manager was known for his hardness and lack of patience.
  • Her hardness towards the mistake seemed unjust.

• Water Quality:

  • The hardness of the water in this region leaves spots on dishes.
  • A water softener can reduce the hardness caused by calcium.

Advanced Usage

• "To test the hardness of": To measure or evaluate how hard a material is.

  • Geologists test the hardness of minerals using a simple scratch test.

• Conceptual "hardness": Used metaphorically to describe abstract resistance or difficulty.

  • The hardness of his heart made forgiveness impossible.
  • They faced the hardness of economic reality.

Variants and Related Words

• Hard (adj): Solid, firm, difficult, severe.

  • The ground was too hard to dig.
  • It was a hard decision to make.

• Harden (verb): To make or become hard.

  • The clay will harden in the sun.
  • His experiences hardened his attitude.

• Hardened (adj): Made hard; or (figuratively) made callous or resistant.

  • Hardened steel is very durable.
  • He was a hardened criminal.

Synonyms

• Physical Property: Firmness, solidity, rigidity.
• Difficulty: Toughness, arduousness, challenge.
• Sternness: Severity, harshness, strictness, callousness.
• Water Quality: (Often described as "mineral content" or "calcium carbonate concentration").

Related Phrases

• Hardness of heart: An idiom meaning stubbornness, lack of pity, or unwillingness to be persuaded.

  • His hardness of heart prevented him from showing mercy.

• Hardness scale: A specific system for measuring hardness (e.g., Mohs hardness scale, Brinell hardness).

  • Talc has a rating of 1 on the Mohs hardness scale.

Noun

1. excessive sternness
   • severity of character
   • the harshness of his punishment was inhuman
   • the rigors of boot camp
2. the quality of being difficult to do
   • he assigned a series of problems of increasing hardness
   • the ruggedness of his exams caused half the class to fail
3. devoid of passion or feeling; hardheartedness
4. a quality of water that contains dissolved mineral salts that prevent soap from lathering
   • the costs of reducing hardness depend on the relative amounts of calcium and magnesium compounds that are present
5. the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale