numeric
Chinese-derived reading used in mahjong, counting, and some compound words. Not the standard Japanese counting word (ご).
from Chinese wǔ
麻雀で「ウー」は五萬子を指す。
In mahjong, 'ウー' refers to the five of characters.
中国語の数字「五」は「ウー」と読む。
The Chinese numeral '五' is read as 'wǔ' (ウー).
Native Japanese kun'yomi for 'five things', used in general counting. ウー is a Sino-Japanese reading with restricted usage.
Borrowed from Chinese wǔ (五), used in Japanese primarily in mahjong terminology and some Sino-Japanese compounds.