insane
- 1Showing an unsound or disordered mind; not sane, or completely mad.
The court found him legally insane and sent him to a psychiatric hospital instead of prison.
In the novel, the lighthouse keeper goes insane after a winter with no one to talk to.
Similarmad, deranged, demented, unhinged
Note
Latin insanus joined in-, "not", to sanus, "sound, sane", so the word describes a mind that is unsound, the plain opposite of sane. It compares in two ways, and both are in use: more insane and most insane, or the shorter insaner and insanest.
- 2Marked by wild excess or utter folly; ridiculous or impractical.
Rents in the city have climbed to insane levels over the past five years.
Driving twelve hours through a snowstorm for one concert was insane, and we knew it.
Similarcrazy, ridiculous, absurd, mad, outrageous
Oppositesensible, reasonable
- 3Extremely good, or so impressive as to seem almost unbelievable.
Did you see her backflip? Her balance is insane.
He's insane at chess and beat the whole club in one afternoon.
Similarincredible, amazing, unreal, phenomenal
Note
This is slang praise that turns a word for madness into a compliment: a gun, a player or someone's work can be insane. It usually follows a linking verb (your work is insane), and with people it takes at, as in insane at FPS games. Said of a person, only context tells it apart from the literal sense of madness, so keep it for casual talk.
- 4
- 5Used by, or relating to, people who are insane.
The old insane asylum on the hill closed decades ago and now stands empty.
Her great-grandfather worked as an attendant in the insane ward of the county hospital.
Similarpsychiatric, mental
Note
Only the position before a noun carries this sense, and there the adjective sorts rather than describes: an insane asylum or an insane hospital is one for people who are insane. Placed after the noun, as in the hospital was insane, it would switch to the "wild folly" meaning.
- 6Bringing on insanity or madness in someone.
Were such things here, as we doe speake about? / Or haue we eaten on the insane Root, / That takes the Reason Prisoner?
c. 1606, William Shakespeare, “The Tragedie of Macbeth”Note
The adjective names the cause here, not the sufferer. Shakespeare's Macbeth, written about 1606, has its speakers wondering whether they have eaten "the insane root / That takes the reason prisoner": the root is not mad, it maddens whoever eats it. Maddening is the word a modern writer would reach for in the same place.
Practice
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Origin
From Latin īnsānus ("unsound in mind; mad, insane"), from in- + sānus ("sound, sane"), equivalent to in- + sane.