medium-sized dish; medium plate
Refers to a plate or dish of medium size, often used in tableware contexts or in set meals.
この定食には、ご飯と味噌汁と中皿が一つ付きます。
This set meal comes with rice, miso soup, and one medium-sized dish.
Compound of 中 (ちゅう, 'middle') and 皿 (さら, 'plate'), literally 'middle plate'.