🇬🇧 en ca 🇦🇩

annulus noun

  /-li/ , /ˈænjəlaɪ/ , /ˈænjələs/ , /ˈænjʊlaɪ/ , /ˈænjʊləs/
  • A ring- or donut-shaped area, object, or structure.
 anell
  • (botany) A structure surrounding a sporangium (or part of it) which shrinks and causes it to rupture for spore dispersal; specifically, in a fern: a structure around about two-thirds of the sporangium consisting of differentially thick-walled cells which dry and distort the sporangium; and in a moss: a complete ring of cells around the tip of the sporangium which dissolves to cause the tip to detach.
 anell, corona circular
  • (geometry) The region in a plane between two concentric circles of different radii.
  • (topology) Any topological space homeomorphic to the region in a plane between two concentric circles of different radii.
 corona circular
Wiktionary Links