also: こめどいや
noun
wholesale rice dealer
A business or person that buys rice in bulk from producers and sells it to retailers or other businesses.
祖父は米問屋を営んでいた。
My grandfather ran a wholesale rice business.
Obsolete kana usage; not used in modern Japanese.
米屋 is a general rice shop, often retail, while 米問屋 specifically refers to a wholesale dealer.
Compound of 米 (こめ, 'rice') + 問屋 (とんや/どんや, 'wholesaler'). The reading どんや is a voiced variant of とんや due to rendaku.