noun🔗ShareA ring- or donut-shaped area or structure."The dartboard featured a red annulus worth double points. "areapartstructureanatomymedicinebiologyChat with AIVocabulary GamePractice Reading
noun🔗ShareThe region in a plane between two concentric circles of different radii."The target around the bullseye had an annulus of blue paint. "mathareaChat with AIVocabulary GamePractice Reading
noun🔗ShareAny topological space homeomorphic to the region in a plane between two concentric circles of different radius."The donut's shape, with its central hole, is an example of an annulus. "mathspaceChat with AIVocabulary GamePractice Reading
noun🔗ShareThe ring of the sun not covered by the moon in an annular solar eclipse."During the annular solar eclipse, a bright annulus of sunlight remained visible around the dark moon. "astronomyspacescienceChat with AIVocabulary GamePractice Reading
noun🔗ShareStructure in a fern that consists of differentially thick-walled cells on a sporangium that bend and distort as a result of drying."The science student observed how the annulus on the fern's sporangium dried and snapped back, scattering spores into the air. "biologyplantstructurepartChat with AIVocabulary GamePractice Reading
noun🔗ShareThe membranous remnants of a partial veil which leaves a ring on the stem of a mushroom."The young mushroom had a prominent annulus, a delicate ring around its stem, showing where the cap had once been connected. "organismplantbiologypartChat with AIVocabulary GamePractice Reading
noun🔗Share(oil and gas production) The space contained between the centre well bore and any external tubing. Sometimes used for separated gas flow."During the well test, engineers monitored the pressure in the annulus to ensure no gas was leaking from the production tubing. "technicalindustryenergyChat with AIVocabulary GamePractice Reading
