English Reference
verb

harden

v.
US /ˈhɑɹdən/ UK /hˈɑːdən/ hard·en UK spelling hardening, hardens

  1. 01 B1 Intermediate

    to become firm, stiff, or solid.

    to transition from a liquid, soft, or malleable state to a solid or rigid one.

    Simple

    Wait for the concrete to harden before you try to walk on it.

    In context

    The molten lava began to harden as soon as it came into contact with the cool ocean water.

    Usage

    Often used as an intransitive verb describing natural processes.

    solidifystiffenset
  2. 02 B1 Intermediate

    to make something firm or solid.

    to cause a substance to become rigid or resistant to pressure.

    Simple

    The cold weather will harden the ground, making it difficult to dig.

    In context

    Special chemicals are added to the mixture to harden the plastic during the manufacturing process.

    Usage

    Used transitively when an external force or agent causes the change.

    toughentemper
  3. 03 B2 Upper Intermediate

    to become more tough or less easily upset by difficult things.

    to become emotionally callous, resilient, or less susceptible to sympathy or pain.

    Simple

    Years of working in the emergency room had hardened his heart to suffering.

    In context

    The soldiers had been hardened by months of combat, showing little emotion even in dire circumstances.

    Usage

    Frequently used with 'heart' or 'attitude' as the object.

    desensitiseinuretoughen
  4. 04 C1 Advanced Technical Computing

    to make a computer system or website safer against hackers.

    to reduce a system's vulnerability by reducing its attack surface and layering technical protections.

    Simple

    The IT team needs to harden the server before we launch the new site.

    In context

    System administrators must harden the operating system by disabling unnecessary services and enforcing strict password policies.

    Usage

    A transitive verb used specifically in the context of cybersecurity.

This entry
Level B1 · Intermediate
Frequency Frequent
Updated