imaginary number
noun
: a complex number (such as 2 + 3i) in which the coefficient of the imaginary unit is not zero
called also imaginary
compare pure imaginaryExamples of imaginary number in a Sentence
Recent Examples on the Web
Perplexity at least plugged some totally imaginary numbers into its formula and gave it a guess, speculating that …
The likelihood of hitting the top of that foul pole worked out to one in every one million balls hit.
—
Jayson Stark, New York Times, 8 May 2026
Then, in 2021, the role of imaginary numbers in quantum theory attracted newfound interest.
—Daniel Garisto, Quanta Magazine, 7 Nov. 2025
This means they are made of both real numbers and the imaginary number i: the square root of negative 1.
—William Ross, The Conversation, 10 Mar. 2025
Other rings of integers can be built out of sets of numbers that include, say, the square root of −1 (the imaginary number that mathematicians call i), or the cube root of 2.
—Joseph Howlett, WIRED, 9 Mar. 2025
There’s imaginary numbers and abstract theoretical math.
—The Editors, JSTOR Daily, 24 Jan. 2024
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Jayson Stark, New York Times, 8 May 2026
Then, in 2021, the role of imaginary numbers in quantum theory attracted newfound interest.
—Daniel Garisto, Quanta Magazine, 7 Nov. 2025
This means they are made of both real numbers and the imaginary number i: the square root of negative 1.
—William Ross, The Conversation, 10 Mar. 2025
Other rings of integers can be built out of sets of numbers that include, say, the square root of −1 (the imaginary number that mathematicians call i), or the cube root of 2.
—Joseph Howlett, WIRED, 9 Mar. 2025
There’s imaginary numbers and abstract theoretical math.
—The Editors, JSTOR Daily, 24 Jan. 2024
Cite this Entry
“Imaginary number.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/imaginary%20number. Accessed 4 Jun. 2026.
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