insane

Pronunciation

• IPA: /ɪnˈseɪn/^[1]

Etymology

It is borrowed from Latin īnsānus (“mad, of unsound mind”),^[2][3][4] from in- (“not”) and sānus (“healthy, sound”).^[2][3] It is related to sane.^[3][2]

Earliest recorded meaning

Of a person, not of sound mind: 1560 in the OED and Barnhart, the 1550s in Etymonline.^[5][3][2] MWU dates it to about 1550.^[6]

Semantic evolution

In 17th-century use it could mean “causing madness”, as Latin insanus did.^[5] The noun use, an insane person, is from 1786, and the plural in such names as insane asylum.^[5][2] Of actions or things, senseless or utterly foolish, is from 1842,^[5][2] and the informal sense “wild, extreme” followed.^[7][8] Insanity is from 1590.^[3]

Timeline

• 1560 – of unsound mind.^[5][3]
• 1590 – insanity.^[3]
• 1605 – causing madness (obsolete).^[5]
• 1786 – an insane person.^[5]
• 1842 – senseless, foolish.^[5]

Modern meaning

Adjective

1. (often offensive) Seriously mentally ill; mad.
2. (law) Not responsible for one's actions because of mental illness.
3. Very foolish or unreasonable: an insane idea.
4. (informal) Wild or extreme.

Word family

• insanely
• insaneness

Related words

• insanity
• sane
• sanitary

References

1. ^ Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
2. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ a b c d e f g h Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
6. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
8. ^ Collins English Dictionary (2023), Glasgow: HarperCollins