/ˈmɪriəd/
[adjective] Used to describe a very large number of things, often too many to count. It can also be used as a noun to mean a huge amount of something.
Myriad once meant exactly 10,000 — the Greeks used it as a precise number, not a vague one.
The story of 'myriad' begins in ancient Greece, where the word 'myrias' (μυριάς) had a very specific and exact meaning: the number 10,000. For the ancient Greeks, this was the largest named number in their everyday counting system, much like how 'thousand' functions for us today. The related adjective 'myrios' (μύριος) meant 'countless' or 'innumerable,' but the noun form was precise and mathematical. Greek soldiers counted their armies in units of ten thousand, and a 'myriarchy' was a military division of exactly that size. The number had real, practical weight in the ancient world.
The word passed into Latin as 'myrias,' keeping its Greek form largely intact because Latin borrowed it directly from Greek scientific and mathematical writing. Latin scholars used it in astronomical and geographical texts when discussing enormous quantities — distances between stars, grains of sand on beaches, the sheer scale of the natural world. Even in Latin, it hovered between the precise and the poetic, used both as an exact count and as a gesture toward the uncountable.
English received 'myriad' in the 16th century, most likely through scholarly Latin texts rather than through any spoken tradition. Early English writers used it primarily in its original numerical sense, meaning exactly 10,000, especially in translations of Greek histories and mathematical works. You can find it in this precise sense in early English Bibles and classical translations, where writers needed a word for a Greek unit that had no clean English equivalent.
Over the following two centuries, however, something interesting happened: the word drifted away from its precise mathematical meaning and became a word about feeling rather than counting. Writers began using 'myriad' the way we use 'countless' or 'infinite' — to suggest an overwhelming abundance rather than a specific total. This shift was almost inevitable. When you use the word for the largest number most people can comfortably imagine, it naturally starts to mean 'more than you can really grasp.' The precision dissolved into poetry.
By the 18th and 19th centuries, Romantic and Victorian writers had fully embraced 'myriad' as a literary word, perfect for describing the stars in the night sky, the leaves on a forest floor, or the feelings in a troubled heart. It carried a sense of grandeur that simpler words like 'many' or 'numerous' could not match. Poets loved it because it felt ancient and vast. Today, both uses survive: 'myriad' as an adjective meaning 'countless' ('myriad possibilities') and as a noun meaning 'a vast number' ('a myriad of stars'), though some careful writers still prefer to avoid the 'a myriad of' construction, seeing it as a departure from the word's original role.