WordWeb Online

1. Not consistent with or using reason
   "irrational fears"; "irrational animals"
    
2. Real but not expressible as the quotient of two integers
   "irrational numbers"

1. A real number that cannot be expressed as a rational number
   - irrational number

Derived forms: irrationals

See also: blind, illogical, incoherent, irrationality, irrationally, nonrational, ratio, reasonless, superstitious, unlogical, unreasonable, unreasoning

Type of: real, real number

Antonym: rational

Encyclopedia: Irrational