insane
/ɪnˈseɪn/
Proposed by a contributor, not yet supported by evidence.
Also seen as: insaner · insanest
Sense 1
Meaning · English
Exhibiting unsoundness or disorder of mind; not sane; utterly mad.
Adjective
Examples
What is the cause of insanity? Nobody can answer such a sweeping question as that, but we know that certain diseases, such as syphilis, break down and destroy the brain cells and result in insanity. In fact, about one-half of all mental diseases can be attributed to such physical causes as brain les
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Sense 2
Meaning · English
Used by or relating to insane people.
Adjective
Examples
an insane hospital
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Common questions
What does “insane” mean?
Exhibiting unsoundness or disorder of mind; not sane; utterly mad.
Is “insane” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.