noun
rice bin; rice chest
A container for storing uncooked rice, traditionally a wooden chest but now often a plastic bin.
新しい米びつを買って、お米を移した。
I bought a new rice bin and transferred the rice into it.
noun
Colloquial metaphor: the person whose earnings support the household, likened to a rice bin that supplies the staple food.
彼が一家の米びつだ。
He is the breadwinner of the family.
Also means 'breadwinner' or 'mainstay', but 大黒柱 is more formal and traditional, while 米びつ is a casual, homely metaphor.
Compound of 米 (こめ, 'rice') and 櫃 (びつ, 'chest, container'). The colloquial sense derives from the idea of the rice bin as the household's essential food supply.