- 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.
- lacking the power to reason
- contrary to reason; 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 irrationalMiddle English ; from Classical Latin irrationalis: see in- and amp; rational
- 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.
(comparative more irrational, superlative most irrational)
- (mathematics): rational