noun
Dental term for the large back teeth used for grinding food.
大臼歯は食べ物をすりつぶす役割をします。
Molars play the role of grinding food.
切歯 are incisors, the front teeth used for cutting, unlike the grinding 大臼歯.
Compound of 大 (large) + 臼歯 (back teeth, molar), where 臼歯 itself is from 臼 (mortar) + 歯 (tooth), referring to the grinding function.