doughnut
/ˈdəʊnʌt/( <美> 亦作 donut)
noun
1- a small fried cake of sweetened dough, typically in the shape of a ball or ring甜甜圈, 炸面圈, 多福饼, 糖纳子。
1.1
- a ring-shaped object, in particular a vacuum chamber in some types of particle accelerator环状物; （尤指某些类型的粒子加速器的真空）环形室