annulus

Fetched 2026-10-26 (cache).

Synonyms: anulus, annuls, angulus

Antonyms: anulus, annuls, angulus

Related words from Datamuse; suggestions, not definitions.

Noun

1. {{senseid|en|ring-shaped area, object, or structure}} A [[ring#Noun|ring]]- or [[donut]]-[[shaped#Adjective|shaped]] [[area]], [[object#Noun|object]]{{,}} or [[structure#Noun|structure]].
2. {{senseid|en|anatomy}}{{lb|en|anatomy}} A ring of [[fibrous]] [[tissue#Noun|tissue]]; specifically {{lb|en|cardiology}}, such a ring around an [[opening#Noun|opening]] of a [[heart#Noun|heart]] [[valve#Noun|valve]], to which the valve [[leaflet#Noun|leaflets]] and [[muscle fiber|muscle fibres]] of the [[atrium|atria]] and [[ventricle]]s are [[attach]]ed; an [[annulus fibrosus cordis]].
3. {{senseid|en|astronomy}}{{lb|en|astronomy}} A ring of [[light#Noun|light]] in a [[celestial body]], especially when [[cause#Verb|caused]] by an [[annular eclipse]] (for example, when the [[Sun]] and [[Moon]] are [[in line]] with the [[Earth]], but the Moon does not [[completely]] [[cover#Verb|cover]] the Sun's [[disc#Noun|disc]]).
4. {{lb|en|biology}}
5. {{lb|en|mathematics}}
6. {{senseid|en|technology}}{{lb|en|technology}} In a [[well#Noun|well]] such as an [[oil well]] or [[water#Noun|water]] well: the [[space#Noun|space]] between a [[pipe#Noun|pipe]] or [[tube#Noun|tube]] and any pipe, tube, [[casing#Noun|casing]], or [[side#Noun|sides]] of a [[hole#Noun|hole]] [[surround#Verb|surrounding]] it.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.