a number that can be expressed exactly by a ratio of two integers.
Origin of rational number
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for rational number
any real number of the form a / b, where a and b are integers and b is not zero, as 7 or 7/3
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Science definitions for rational number
A number that can be expressed as an integer or a quotient of integers. For example, 2, -5, and 12 are rational numbers.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.