toroidal

/tɔˈrɔɪdəl/
adjective
  1. Shaped like a torus (a donut shape); having a surface like a ring or inner tube.
    • The toroidal shape of the magnetic field helps contain the plasma in a fusion reactor.
    • The sculpture was a large toroidal ring made of polished steel, rotating slowly in the gallery.
    • She designed a toroidal coil for the electronics project, winding the wire around a donut-shaped core.
Antonyms