Definition of irrational number
: a number that can be expressed as an infinite decimal with no set of consecutive digits repeating itself indefinitely and that cannot be expressed as the quotient of two integers
First Known Use of irrational number
Learn More about irrational number
Britannica.com: Encyclopedia article about "irrational number"
Seen and Heard
What made you want to look up irrational number? Please tell us where you read or heard it (including the quote, if possible).