annulus

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English[edit]

Noun[edit]

annulus (plural annuluses or annuli)

  1. A ring- or donut-shaped area or structure.
  2. (geometry) The region in a plane between two concentric circles of different radius.
  3. (topology) Any topological space homeomorphic to the region in a plane between two concentric circles of different radius.
  4. (astronomy) The ring of the sun not covered by the moon in an annular solar eclipse.
  5. (botany) Structure in a fern that consists of differentially thick-walled cells on a sporangium that bend and distort as a result of drying.
  6. (mycology) The membranous remnants of a partial veil which leaves a ring on the stem of a mushroom.
  7. (oil and gas production) The space contained between the centre well bore and any external tubing. Sometimes used for separated gas flow.

Synonyms[edit]

Hyponyms[edit]

  • (ring-shaped structure): torus

Derived terms[edit]

Translations[edit]


Latin[edit]

Pronunciation[edit]

Noun[edit]

ānnulus m (genitive ānnulī); second declension

  1. Alternative form of ānulus.

Inflection[edit]

Second declension.

Number Singular Plural
nominative ānnulus ānnulī
genitive ānnulī ānnulōrum
dative ānnulō ānnulīs
accusative ānnulum ānnulōs
ablative ānnulō ānnulīs
vocative ānnule ānnulī