doughˈnut or (esp US) donut noun

1. A ring or ball of sweetened dough fried in fat
2. Any object shaped like a ring
3. An accelerating tube in the form of a toroid (nucleonics)
4. A toroidal assembly of enriched fissile material for increasing locally the neutron intensity in a reactor for experimental purposes, a tokamak (also toroid; nucleonics)
5. A pile of annular laminations in toroidal shape for magnetic testing or a loading coil in toroidal shape on transmission lines, permitting exact balance in addition to inductance (elec eng)

intransitive verb

To practise doughnutting

doughˈnutting noun

The surrounding of a speaker in parliament by other members to give an impression, esp to television viewers, of a packed house

torus /tōˈ, töˈrəs/

1. A large moulding, semicircular or nearly so in section, common at the base of a column (architecture)
2. A figure generated by the revolution of a circle or other conic section about a straight line in its own plane (geometry)
3. The receptacle of a flower (botany)
4. A ridge or prominence (zoology, anatomy)
5. A ring-shaped discharge-tube

tore /tōr, tör/ noun (architecture and geometry)

A torus

toric /torˈ, tōrˈ, törˈ/ adjective

Of or having the form of a torus or a part of a torus

toroid /torˈ, tōrˈ, törˈ/ adjective

Shaped like an anchor-ring

A coil or transformer of that shape

toroidˈal adjective