imaginary unit

noun

: the positive square root of minus 1 denoted by i or + √-1

Example Sentences

Recent Examples on the Web The introduction of this one new non-real number — i, the imaginary unit — launched an entirely new mathematical world to explore. —

Quanta Magazine, 25 Oct. 2018

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'imaginary unit.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

circa 1911, in the meaning defined above

Time Traveler

The first known use of imaginary unit was circa 1911

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Dictionary Entries Near imaginary unit

imaginary part

imaginary unit

imagination

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Cite this Entry

Style

“Imaginary unit.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/imaginary%20unit. Accessed 27 May. 2023.

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