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insane

[in-seyn] /ɪnˈseɪn/
adjective
1.
not sane; not of sound mind; mentally deranged.
2.
of, relating to, or characteristic of a person who is mentally deranged:
insane actions; an insane asylum.
3.
utterly senseless:
an insane plan.
Origin of insane
1550-1560
From the Latin word insānus, dating back to 1550-60. See in-3, sane
Related forms
insanely, adverb
insaneness, noun
pseudoinsane, adjective
Synonyms
1. demented; lunatic, crazed, crazy; maniacal. 3. foolish, irrational. See mad.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
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Examples from the Web for insane
Contemporary Examples
Historical Examples
  • Schwitter, the nurseryman, had proved to have a wife in an insane asylum.

    K Mary Roberts Rinehart
  • The adoration of her, and the insane desire of her, can be seen in every play he wrote from 1597 to 1608.

    The Man Shakespeare Frank Harris
  • Advocated with more heat than light by the outmates of every asylum for the insane.

    The Devil's Dictionary Ambrose Bierce
  • He, and he alone, in this insane city, will wait at table (the Chinaman doesn't count).

    American Notes Rudyard Kipling
  • And the fancy was this: Are not the sane and the insane equal at night as the sane lie a dreaming?

    The Uncommercial Traveller Charles Dickens
British Dictionary definitions for insane

insane

/ɪnˈseɪn/
adjective
1.
  1. mentally deranged; crazy; of unsound mind
  2. (as collective noun; preceded by the): the insane
2.
characteristic of a person of unsound mind: an insane stare
3.
irresponsible; very foolish; stupid
Derived Forms
insanely, adverb
insaneness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for insane
adj.

1550s, from Latin insanus "mad, insane; outrageous, excessive, extravagant," from in- "not" (see in- (1)) + sanus "well, healthy, sane" (see sane). Originally only of persons; of actions, from 1842. Cf. lunatic; and Italian pazzo "insane," originally a euphemism, from Latin patiens "suffering." German verrückt, literally past participle of verrücken "to displace," "applied to the brain as to a clock that is 'out of order' " [Buck]. The noun meaning "insane person" is attested from 1786.

Online Etymology Dictionary, © 2010 Douglas Harper
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insane in Medicine

insane in·sane (ĭn-sān')
adj.
Of, exhibiting, or afflicted with insanity.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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