Translation guide
The English word "myriad" can be used as a noun meaning a countless number or as an adjective meaning innumerable. In Japanese, there is no single direct equivalent; instead, various expressions convey the idea of a vast, uncountable number. The most common and versatile option is 無数 (むすう), which works in both formal and casual contexts. Other options include 数え切れない (かぞえきれない) for an emotional, emphatic tone, and more literary or formal terms like 幾多 (いくた) and 万 (ばん).
Expressing a vast, uncountable number of things or people.
The most direct and common translation for 'myriad' as a noun. It means 'countless number' and can be used in both spoken and written Japanese. It is neutral in register.
A myriad of stars shone in the night sky.
He has overcome a myriad of difficulties.
Literally 'so many you can't count them all'. This phrase is more emphatic and slightly more casual than 無数. It conveys a sense of overwhelming quantity.
A myriad of people participated in the event.
A formal, somewhat literary term meaning 'many' or 'countless'. Often used in written language or formal speeches. It can sound stiff in casual conversation.
After a myriad of trials, he achieved success.
Literally 'ten thousand', but used in compounds to mean 'myriad' or 'all kinds of'. It appears in set phrases like 万物 (ばんぶつ, all things) or 万感 (ばんかん, myriad emotions). Not used alone as a noun in modern Japanese.
With a myriad of emotions, he wrote the letter.
Describing something as countless or innumerable.
There is no exact Japanese word that covers all uses of 'myriad'. Using 万 (まん) alone to mean 'myriad' is unnatural. Instead, use 無数 or 数え切れない depending on the context.
無数 is more neutral and can be used in formal writing. 数え切れない is more emphatic and conversational, emphasizing the inability to count. Both are common, but 無数 is slightly more versatile.
The shorter form of 数え切れないほどの, used directly before a noun. It means 'countless' and is slightly more colloquial than 無数の.
She has read a myriad of books.