A Japanese numeral meaning ten thousand, the next degree after sen (one thousand), hyaku (one hundred), and juu (ten). This is also where Japanese diverges from most Western representations of large numbers: for example, one hundred thousand is represented as juu-man, literally "ten ten-thousands". This continues with hyaku-man (one million; hundred ten-thousands) and sen-man (ten million; thousand ten-thousands), until you get to oku (one hundred millon; ten thousand ten-thousands).
Can be written as 万, and ten thousand is sometimes written as 1,0000 in more traditional contexts.