noun
tens of thousands of years; eternity
Emphatic expression for an immensely long time, stronger than 万年. Often used in hyperbolic or poetic contexts to mean 'forever'.
See also: 万年
この伝統は万万年も続いてきたように感じられる。
This tradition feels as if it has continued for tens of thousands of years.
万万年の時を経ても、その輝きは失われない。
Even after an eternity, its brilliance will not fade.
万年 means 'ten thousand years' or 'a very long time', while 万万年 is more emphatic, suggesting an even longer or eternal span.
Reduplication of 万 (ten thousand) and 年 (year), literally 'ten-thousand ten-thousand years', used for hyperbolic emphasis.