### Irrational

*-adverb*

1. without the faculty of reason; deprived of reason.

2. without or deprived of normal mental clarity or sound judgment.

3. not in accordance with reason; utterly illogical: *irrational arguments*.

4. not endowed with the faculty of reason: *irrational animals*.

5. *Mathematics*.

a. (of a number) not capable of being expressed exactly as a ratio of two integers.

b. (of a function) not capable of being expressed exactly as a ratio of two polynomials.

6. *Algebra*. (of an equation) having an unknown under a radical sign or, alternately, with a fractional exponent.

7. *Greek and Latin Prosody*.

a. of or pertaining to a substitution in the normal metrical pattern, esp. a long syllable for a short one.

b. noting a foot or meter containing such a substitution.

*-noun*

8. *Mathematics*. irrational number.