<p><strong>Adjective</strong></p><ul><li>without the faculty of reason</li><li>deprived of reason</li><li>without or deprived of normal mental clarity or sound judgment</li><li>not in accordance with reason</li><li>utterly illogical</li></ul><p><strong>Synonyms</strong></p><ul><li>insensate</li><li>ridiculous</li><li>unreasonable</li></ul><p><strong>Description</strong></p><ul><li>not endowed with the faculty of reason</li><li>irrational animals</li></ul><p><strong>Mathematics</strong></p><ul><li>(of a number) not capable of being expressed exactly as a ratio of two integers</li><li>(of a function) not capable of being expressed exactly as a ratio of two polynomials</li><li>(of an equation) having an unknown under a radical sign or, alternately, with a fractional exponent</li></ul><p><strong>Greek and Latin Prosody</strong></p><ul><li>of or relating to a substitution in the normal metrical pattern, especially a long syllable for a short one</li><li>noting a foot or meter containing such a substitution</li></ul><p><strong>Noun</strong></p><ul><li>Mathematics. irrational number</li></ul>