insane Definition

  • 1mentally ill; exhibiting serious and debilitating mental disorders
  • 2extremely foolish or irrational; absurd or ridiculous

Using insane: Examples

Take a moment to familiarize yourself with how "insane" can be used in various situations through the following examples!

  • Example

    He was declared legally insane and sent to a mental institution.

  • Example

    The idea that the earth is flat is insane.

  • Example

    She has an insane amount of energy.

  • Example

    The roller coaster ride was insane!

insane Synonyms and Antonyms

Synonyms for insane

Antonyms for insane

Idioms Using insane

  • to be completely crazy or insane


    After spending years alone in the wilderness, he was as mad as a hatter.

  • to become mentally ill or lose one's mind


    The stress of the job was so great that he eventually went insane.

  • like a madman/woman

    to do something with great intensity or urgency


    He was running like a madman to catch the train.

Phrases with insane

  • to make someone extremely angry or frustrated


    The constant noise from the construction site is driving me insane.

  • a hospital for mentally ill people


    He spent several months in an insane asylum after his breakdown.

  • laughter that is uncontrollable and often associated with mental illness


    His insane laughter echoed through the empty halls of the abandoned building.

Origins of insane

from Latin 'insanus', meaning 'unhealthy'


Summary: insane in Brief

The term 'insane' [ɪnˈseɪn] refers to a state of serious mental illness or extreme irrationality. It can describe a person or an idea, as in 'The idea that the earth is flat is insane.' 'Insane' is used in phrases like 'drive someone insane,' and idioms like 'be as mad as a hatter,' which means to be completely crazy. 'Insane' has formal synonyms like 'mentally ill' and 'psychotic,' and informal synonyms like 'crazy' and 'nuts.'

How do native speakers use this expression?