Insane vs. Irrational — What's the Difference?

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

Not endowed with reason.

Characteristic of or associated with persons who are mentally deranged

Affected by loss of usual or normal mental clarity; incoherent, as from shock.

Intended for use by such persons

Marked by a lack of accord with reason or sound judgment

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

Being a syllable in Greek and Latin prosody whose length does not fit the metric pattern.

Immoderate; wild

Being a metric foot containing such a syllable.

Very foolish; absurd

(Mathematics) Of or relating to an irrational number.

Exhibiting unsoundness or disorder of mind; not sane; utterly mad.

An irrational number.

Used by or relating to insane people.

Not rational; unfounded or nonsensical.

Causing insanity or madness.

Of a real number, that cannot be written as the ratio of two integers.

(informal) Characterized by insanity or the utmost folly; ridiculous; impractical.

A real number that can not be expressed as the quotient of two integers, an irrational number.

(slang) Extremely good; incredibly amazing.

Not rational; void of reason or understanding; as, brutes are irrational animals.

Exhibiting unsoundness or disorder of mind; not sane; mad; deranged in mind; delirious; distracted. See Insanity, 2.

Not according to reason; having no rational basis; clearly contrary to reason; easily disproved by reasoning; absurd; - of assertions and beliefs.

Used by, or appropriated to, insane persons; as, an insane hospital.

Not capable of being exactly expressed by an integral number, nor by a ratio of integral numbers; surd; - said especially of roots. See Surd.

Causing insanity or madness.

Not consistent with or using reason;

Characterized by insanity or the utmost folly; chimerical; unpractical; as, an insane plan, attempt, etc.

Real but not expressible as the quotient of two integers;

Afflicted with or characteristic of mental derangement;

Very foolish;