Insane Definition

ĭn-sān

adjective

Of, exhibiting, or afflicted with mental derangement. Not used in psychiatric diagnosis.

American Heritage

Not sane; mentally ill or deranged; demented; mad.

Webster's New World

Of or for insane people.

An insane asylum.

Webster's New World

Intended for use by such persons.

An insane asylum.

American Heritage

Having been determined to be in a condition that meets the legal definition of insanity.

American Heritage

Synonyms:

Antonyms:

Origin of Insane

From Latin īnsānus (“unsound in mind; mad, insane”), from in- + sānus (“sound, sane”).

From Wiktionary
Latin īnsānus in- not in–¹ sānus sane, healthy

From American Heritage Dictionary of the English Language, 5th Edition