noun
three Tokugawa branch families; Gosanke
Historical term for the three senior branch houses of the Tokugawa shogunate: Owari, Kii, and Mito. Used in discussions of Edo-period politics and succession.
See also: 三家
御三家は、尾張・紀伊・水戸の徳川家を指す。
The Gosanke refers to the Tokugawa families of Owari, Kii, and Mito.
noun
big three; top three
By extension, refers to the three most prominent or dominant entities in any field, such as companies, schools, or products. Often used in media and casual conversation.
この業界の御三家と言えば、A社、B社、C社だ。
When it comes to the big three in this industry, it's Company A, Company B, and Company C.
アイドルグループの御三家として知られている。
They are known as the top three idol groups.
From 御 (honorific prefix) + 三 (three) + 家 (family/house). Originally referred to the three senior Tokugawa branch families; the extended sense 'big three' developed by analogy.