adjective

- Irrational is defined as lacking reason or understanding.
An example of irrational is a fear of a certain color.

- The definition of an irrational is a number that cannot be expressed as a fraction.
An example of irrational is pi.

## irrational

- lacking the power to reason
- contrary to reason or rationality; senseless; unreasonable; absurd
- Math. designating a real number not expressible as an integer or as a quotient of two integers: ? and pi are irrational numbers

Origin of irrational

Middle English ; from Classical Latin*irrationalis*: see in- and amp; rational

## irrational

adjective

**a.**Not endowed with reason.**b.**Affected by loss of usual or normal mental clarity; incoherent, as from shock.**c.**Marked by a lack of accord with reason or sound judgment:*an irrational dislike.***a.**Being a syllable in Greek and Latin prosody whose length does not fit the metric pattern.**b.**Being a metric foot containing such a syllable.-
*Mathematics*Of or relating to an irrational number.

noun

*Mathematics*

An irrational number.

*Related Forms:*

**ir·ra′tion·al·ly**adverb

**ir·ra′tion·al·ness**noun

## irrational

Adjective

(*comparative* more irrational, *superlative* most irrational)

- Not rational; unfounded or nonsensical.
*an irrational decision*

- (mathematics, arithmetic, number theory, not comparable) Of a real number, that cannot be written as the ratio of two integers.
*The number π is irrational.*

Hyponyms

- (mathematics): transcendental

Noun

(*plural* irrationals)

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

Origin

From Latin *irratiōnālis*, from *ir-* + *ratiōnālis*.