Dictionary.com

imaginary number

Save This Word!

noun Mathematics.
Also called imaginary, pure imaginary number. a complex number having its real part equal to zero.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?

Origin of imaginary number

First recorded in 1905–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use imaginary number in a sentence

British Dictionary definitions for imaginary number

imaginary number

noun
any complex number of the form i b, where i = √–1
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

Scientific definitions for imaginary number

imaginary number
[ ĭ-măjə-nĕr′ē ]

A type of complex number in which the multiple of i (the square root of -1) is not equal to zero. Examples of imaginary numbers include 4i and 2 - 3i, but not 3 + 0i (which is just 3). See more at complex number.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK