# Myriad

A **myriad** is, in its original and precise sense, the number ten thousand (10,000); in modern English it is more often used loosely to mean an indefinitely great number of things, both as a noun ("a myriad of reasons") and as an adjective ("myriad reasons").<sup>[1](https://www.dictionary.com/browse/myriad)</sup><sup> • </sup><sup>[2](https://ahdictionary.com/word/search.html?q=myriad)</sup>

| Key fact | Detail |
|---|---|
| Exact value | 10,000; historically the largest number named by a single word in ancient Greek<sup>[3](https://www.etymonline.com/word/myriad)</sup><sup> • </sup><sup>[4](https://numberwise.app/number/10000)</sup> |
| Greek source | μυριάς (myrias, genitive myriados), "a number of ten thousand," from μυρίος (myrios), "innumerable, countless"<sup>[2](https://ahdictionary.com/word/search.html?q=myriad)</sup><sup> • </sup><sup>[3](https://www.etymonline.com/word/myriad)</sup> |
| Entry into English | 1550s, from French *myriade* and Late Latin *myrias*, first meaning "the number of 10,000" and also "an indefinitely great number"<sup>[3](https://www.etymonline.com/word/myriad)</sup> |
| Greek numeral symbol | In the Ionic Greek alphabetic system, 10,000 had the special symbol M (capital mu)<sup>[5](https://online.math.uh.edu/Math2303-unpaid/ch1/s12/2303-Section-12.pdf)</sup> |
| Archimedes' use | The *Sand Reckoner* counts in groups of 10,000; numbers up to a myriad myriads (100,000,000) form the "first numbers"<sup>[6](https://web.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/Ch.3/Ch3.html)</sup><sup> • </sup><sup>[7](https://www.aproged.pt/biblioteca/worksofarchimede.pdf)</sup> |
| East Asian unit | 10,000 (Chinese 萬/万 *wàn*, Japanese *man*) is the base grouping unit in Chinese, Japanese, and Korean number naming, giving a new name every four zeros rather than every three<sup>[4](https://numberwise.app/number/10000)</sup><sup> • </sup><sup>[8](https://doi.org/10.1163%2F22105018-02602003)</sup> |
| English usage | Historically a noun; adjectival use began in 1800s poetry; both noun and adjective uses are accepted today<sup>[2](https://ahdictionary.com/word/search.html?q=myriad)</sup> |

## Etymology and Greek meaning

The English word descends through French *myriade* and [Late Latin](https://www.edgepedia.org/late-latin) *myrias* (genitive *myriadis*) from [Ancient Greek](https://www.edgepedia.org/ancient-greek) μυριάς (myrias), "a number of ten thousand; countless numbers," itself from μυρίος (myrios), "innumerable, countless, infinite; boundless," which as a definite number meant ten thousand.<sup>[3](https://www.etymonline.com/word/myriad)</sup> The lexicographers Liddell and Scott described myrios as "the greatest number in Greek expressed by one word."<sup>[3](https://www.etymonline.com/word/myriad)</sup> The deeper origin is uncertain: a possible Indo-European root *meue-, "abundant," has been proposed, while the etymologist Robert Beekes records "no etymology."<sup>[3](https://www.etymonline.com/word/myriad)</sup>

The noun μυριάς is also the source of the plural form μύριοι (myrioi), "ten thousand," which survives in [Modern Greek](https://www.edgepedia.org/modern-greek) counting.<sup>[9](https://en.wiktionary.org/wiki/%CE%BC%CF%8D%CF%81%CE%B9%CE%BF%CE%B9)</sup>

## The myriad in Greek mathematics

Ancient Greek had ordinary number words up to a thousand, with the myriad as the largest single-word number, and the alphabetic numeral system gave 10,000 its own symbol, the capital letter M.<sup>[3](https://www.etymonline.com/word/myriad)</sup><sup> • </sup><sup>[5](https://online.math.uh.edu/Math2303-unpaid/ch1/s12/2303-Section-12.pdf)</sup> To write larger numbers, Greeks used powers of the myriad: a myriad (10,000) was a *first myriad* (πρώτη μυριάς), a second myriad (δευτέρα μυριάς) was 10,000², and so on, written M, MM, and beyond.<sup>[10](https://www.ms.uky.edu/~sohum/ma330/files/HeathVolI.pdf)</sup> The mathematician Apollonius, in a lost arithmetical work known through Pappus's commentary, called these successive powers "simple myriads," "double myriads," "triple myriads," meaning 10,000, 10,000², 10,000³, and so on.<sup>[10](https://www.ms.uky.edu/~sohum/ma330/files/HeathVolI.pdf)</sup> On this scheme a myriad myriads, 10,000 × 10,000, equals 100,000,000, what the sources of Archimedes' era called the limit of the ordinary system.<sup>[11](https://www.numdam.org/item/10.24033/rhm.126.pdf)</sup>

**Archimedes' Sand Reckoner.** To show that a notation for far larger numbers was possible, [Archimedes](https://www.edgepedia.org/archimedes) built his system on the myriad.<sup>[4](https://numberwise.app/number/10000)</sup> He named the numbers up to "ten-thousand myriads" (10,000 × 10,000, or 10⁸) the *first numbers*; a myriad myriads of first numbers became one unit of the *second numbers*, and the same construction repeated for third numbers and beyond, each order of numbers running from units through decads, hekatontads, chiliads, and myriads up to ten-thousand myriads.<sup>[6](https://web.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/Ch.3/Ch3.html)</sup> Because he counted in groups of 10,000, modern editions of the *Sand Reckoner* separate his numbers with a comma after the fourth digit rather than the third, writing 10,0000 where English convention writes 100,000.<sup>[12](https://web.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/SandReckoner.html)</sup> The treatise used this system to bound the number of sand grains that could fill a sphere the size of the then-modeled universe, in which the diameter of the world was taken as less than one hundred myriad myriad stadia.<sup>[13](https://tile.loc.gov/storage-services/master/gdc/gdcebookspublic/20/21/75/85/26/2021758526/2021758526.pdf)</sup>

The precise sense survives in English mainly in references to ancient Greece, as in the historian Thirlwall's phrase about 4,000 men from the Peloponnesus fighting at [Thermopylae](https://www.edgepedia.org/thermopylae) "with 300 myriads."<sup>[14](https://art19.com/shows/merriam-websters-word-of-the-day/episodes/36d24de6-f27f-4491-8fc8-037c965604a1)</sup>

## The myriad as a counting unit in East Asia

Chinese number naming has always used a series of decimal pivots at 10, 100, 1,000, and 10,000, and 10,000 (萬, *wàn*) remains the unit at which Chinese, Japanese, and Korean introduce a new number name, so these languages group digits in fours rather than threes.<sup>[15](https://arxiv.org/abs/1810.11233)</sup><sup> • </sup><sup>[4](https://numberwise.app/number/10000)</sup> A number such as 100,000, which English reads as one hundred thousand, is written and read in the myriad system as 10,0000, ten myriads.<sup>[4](https://numberwise.app/number/10000)</sup> The logograms for 10, 100, 1,000, and 10,000 (shi 十, bai 百, qian 千, wan 萬) appear consistently on [Shang dynasty](https://www.edgepedia.org/shang-dynasty) oracle bones (c. 1600–1046 BCE) and Zhou bronze inscriptions, showing that the four-decimal structure is among the oldest attested features of Chinese numeration.<sup>[8](https://doi.org/10.1163%2F22105018-02602003)</sup>

Ancient Chinese mathematical texts even describe competing large-number schemes organized around the myriad. In the middle of the three-tier systems recorded in the *Shushu Jiyi*, numbers advance by myriads: ten thousand myriads are called *oku* (億), ten thousand *oku* are called *cho*, and ten thousand *cho* are called *kyo*; the lower tier instead advances by tens, with ten myriads called *oku*.<sup>[16](https://soroban-museum.note.jp/n/n1eae4cd36cb4?hl=en)</sup>

## Usage in English

According to the American Heritage Dictionary usage note, throughout most of its history in English it was used as a noun, as in "a myriad of reasons"; in the 1800s it began to appear in poetry as an adjective, as in "myriad dreams," a use so well entrenched that many people came to consider it the only correct one, although both uses are accepted today.<sup>[2](https://ahdictionary.com/word/search.html?q=myriad)</sup> [Samuel Taylor Coleridge](https://www.edgepedia.org/samuel-taylor-coleridge)'s line "Myriad myriads of lives" combines the two.<sup>[2](https://ahdictionary.com/word/search.html?q=myriad)</sup>


## References

1. [Myriad Definition & Meaning, Dictionary.com](https://www.dictionary.com/browse/myriad)
2. [Myriad, American Heritage Dictionary of the English Language](https://ahdictionary.com/word/search.html?q=myriad)
3. [Myriad, Etymology, Origin & Meaning, Etymonline](https://www.etymonline.com/word/myriad)
4. [10,000, Mathematical Properties and Representations, Numberwise](https://numberwise.app/number/10000)
5. [Alphabetic and Multiplicative Systems of Numeration, Math 2303, University of Houston](https://online.math.uh.edu/Math2303-unpaid/ch1/s12/2303-Section-12.pdf)
6. [Archimedes, The Sand-Reckoner, chapter 3, translated by Henry Mendell](https://web.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/Ch.3/Ch3.html)
7. [The Works of Archimedes, The Sand-Reckoner](https://www.aproged.pt/biblioteca/worksofarchimede.pdf)
8. [From Zero to Infinity, Inner Asia 26(2), 2024](https://doi.org/10.1163%2F22105018-02602003)
9. [μύριοι and myriad, Wiktionary](https://en.wiktionary.org/wiki/%CE%BC%CF%8D%CF%81%CE%B9%CE%BF%CE%B9)
10. [A History of Greek Mathematics, Thomas Heath, Vol. I](https://www.ms.uky.edu/~sohum/ma330/files/HeathVolI.pdf)
11. [Revue d'histoire des mathématiques, on Archimedes' number system](https://www.numdam.org/item/10.24033/rhm.126.pdf)
12. [Archimedes, Sand-Reckoner, introduction and translation notes, Henry Mendell](https://web.calstatela.edu/faculty/hmendel/Ancient%20Mathematics/Archimedes/SandReckoner/SandReckoner.html)
13. [Archimedes and his Sandreckoner, Library of Congress digitized volume](https://tile.loc.gov/storage-services/master/gdc/gdcebookspublic/20/21/75/85/26/2021758526/2021758526.pdf)
14. [Merriam-Webster's Word of the Day, episode on "myriad"](https://art19.com/shows/merriam-websters-word-of-the-day/episodes/36d24de6-f27f-4491-8fc8-037c965604a1)
15. [Chinese Names for Integers, arXiv:1810.11233](https://arxiv.org/abs/1810.11233)
16. [Changes in Large Number Naming Systems and Positional Notation in Jinkoki, Soroban Museum](https://soroban-museum.note.jp/n/n1eae4cd36cb4?hl=en)
17. [myriad - wiktionary, the free dictionary](https://en.wiktionary.org/wiki/myriad)

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*Topic: Encyclopedia › Physical world and mathematics › Mathematics and statistics › Numbers and algebra › Arithmetic and number systems › Integer sequences and partitions › Special and named integers › Named large numbers and number naming systems*

*Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026; Oct 15, 2026 · Edited: Sep 30, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 15, 2026*

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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license