Noun

• S: (n) irrational number, irrational (a real number that cannot be expressed as a rational number)
• direct hyponym / full hyponym
• S: (n) transcendental number (an irrational number that is not algebraic)
• S: (n) pi (the ratio of the circumference to the diameter of a circle; approximately equal to 3.14159265358979323846...)
• S: (n) e (the base of the natural system of logarithms; approximately equal to 2.718282...)
• S: (n) algebraic number (root of an algebraic equation with rational coefficients)
• direct hypernym / inherited hypernym / sister term

Adjective

• S: (adj) irrational (not consistent with or using reason) "irrational fears"; "irrational animals"
• see also
• similar to
• antonym
• derivationally related form
• W: (n) irrationality [Related to: irrational] (the state of being irrational; lacking powers of understanding)
• S: (adj) irrational (real but not expressible as the quotient of two integers) "irrational numbers"