English Reference
noun

hardness

n.
US /ˈhɑɹdnəs/ UK /hˈɑːdnəs/ hard·ness UK spelling hardnesses

  1. 01 B2 Upper Intermediate

    the quality of being firm and solid, not soft or easy to bend.

    the physical quality of being rigid or resistant to pressure; the state of being solid in texture.

    Simple

    The hardness of the mattress made it difficult for him to sleep comfortably.

    In context

    The geologist tested the hardness of the rock sample to determine its mineral composition and structural integrity.

  2. 02 C1 Advanced Technical Science

    how much a material can resist being scratched or dented.

    the resistance of a solid material to various kinds of permanent shape change when a force is applied.

    Simple

    Diamonds are famous for their extreme hardness, as they can scratch almost any other surface.

    In context

    Engineers must account for the surface hardness of the alloy to ensure the gears do not wear down prematurely under high friction.

    malleability
  3. 03 C1 Advanced Technical Science

    the amount of minerals, like calcium, found in water.

    the concentration of dissolved calcium and magnesium salts in water, affecting its reaction with soap.

    Simple

    High water hardness can cause white scales to build up inside your kettle.

    In context

    The technician measured the water hardness in parts per million to determine if a commercial softener was required for the boiler system.

    mineral content
  4. 04 C1 Advanced Literary

    a quality of being cold, strict, or showing no sympathy.

    a lack of sensitivity, compassion, or gentleness in a person's character or actions.

    Simple

    She was surprised by the hardness in his voice when he told her to leave.

    In context

    The novel explores the hardness of the protagonist's heart, forged by years of betrayal and social isolation.

    harshnessseveritycallousness

From Middle English hardness, hardnesse, from Old English heardnes, from heard + -nes, equivalent to hard + -ness.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Old English heardnes
Level B2 · Upper Intermediate
Frequency Occasional
Updated