annulus

English

Noun

annulus (plural annuluses or annuli)

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

Hyponyms

• (ring-shaped structure): torus

Derived terms

• annulate
• annulation

Translations

ring-shaped structure

Aragonese: aniello (an) m. Asturian: aniellu (ast) m. Catalan: anell (ca) m. Corsican: anellu (co) m. French: anneau (fr) m. Galician: anel (gl) m.

Italian: anello (it) m. Latin: anulus (la) m. Portuguese: anel (pt) m. Romanian: inel (ro) n. Spanish: anillo (es) m.

botany: structure in a fern

Hungarian: annulusz (hu)

mycology: membranous remnants

Spanish: anillo (es) m.

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Latin

Noun

ānnulus (genitive ānnulī); m, second declension

1. Alternative form of ānulus.

Inflection

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