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Related to annulus: Annulus fibrosus, Annulus of Zinn


n. pl. an·nu·lus·es or an·nu·li (-lī′)
1. A ringlike figure, part, structure, or marking, such as a growth ring on the scale of a fish.
a. A ring or group of thick-walled cells around the sporangia of many ferns that functions in spore release.
b. The ringlike remains of a broken partial veil, found around the stipes of certain mushrooms.
3. Mathematics The figure bounded by and containing the area between two concentric circles.

[Latin ānulus, ring, diminutive of ānus.]


n, pl -li (-ˌlaɪ) or -luses
1. (Mathematics) the area between two concentric circles
2. a ring-shaped part, figure, or space
[C16: from Latin, variant of ānulus ring]


(ˈæn yə ləs)

n., pl. -li (-ˌlaɪ)
1. a ringlike part, band, or space; ring.
2. the space between two concentric circles on a plane.
3. the veil remnant on a mushroom stalk.
4. a growth ring, as the annual ring of a tree trunk, that can be used to estimate age.
[1555–65; < Latin, variant of ānulus=ān(us) ring + -ulus -ule]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.annulus - a toroidal shapeannulus - a toroidal shape; "a ring of ships in the harbor"; "a halo of smoke"
fairy circle, fairy ring - a ring of fungi marking the periphery of the perennial underground growth of the mycelium
toroid - the doughnut-shaped object enclosed by a torus
2.annulus - (Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collarannulus - (Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collar
Fungi, fungus kingdom, kingdom Fungi - the taxonomic kingdom including yeast, molds, smuts, mushrooms, and toadstools; distinct from the green plants
plant part, plant structure - any part of a plant or fungus
partial veil - membrane of the young sporophore of various mushrooms extending from the margin of the cap to the stem and is ruptured by growth; represented in mature mushroom by an annulus around the stem and sometimes a cortina on the margin of the cap


[ˈænjʊləs] n (annules or annuli (pl)) [ˈænjʊˌlaɪ]corona circolare
References in periodicals archive ?
Nucleus pulposus and annulus fibrosus regions were identified, several regions of interest were chosen, and their ADC values were obtained.
As standard, Tecno Plugs feature two elastomeric seals, the dual-seal configuration providing an annulus void which is pressure-tested to verify both seals are leak-tight.
1-3) In this article, we introduce the mobilization of the mastoid segment of the facial nerve during the elevation of the tympanic annulus by a straight microneedle in a myringoplasty operation.
ABSTRACT Age data play an important role in the Atlantic surfclam [Spisula solidissima (Dillwyn, 1817)] stock assessment and their accuracy depends on understanding the periodicity and timing of annulus formation.
Dorsal-fin spines had well-defined annuli, but vascularization near the core prevented consistent identification of the first annulus and led to biased ages.
Sustained annulus pressure or casing-to-casing annulus pressure as a result of the inherent weakness of cement in wells continues to plague the industry," commented Abdullah Osama Abdelwahed, well completion sales director at Welltec "We see an increasing number of operators being concerned with cement as a standalone barrier, seeking alternatives both because of the difficulties to deploy cement and the long-term risk.
is a genus of agaricoid, mushroom-forming fungi, which are characterized by the presence of partial veil usually forming an annulus or leaving remnants at the pileus margin, adnate to adnexed lamellae and well-developed rhizomorphs on stipe base, which are densely covered by spiniform crystals called acanthocytes, the latter considered a diagnostic feature of the genus (Farr, 1980; Cortez & Silveira, 2008).
Immediate percentage reduction in gradient across PV and complications in either group were analyzed along with frequency of RV dysfunction, balloon to annulus ratio, pre dilatation and balloon stabilization.
The area A can be obtained via calculus by dividing the annulus up into an infinite number of annuli of infinitesimal width d[chi] and area 2[pi][chi]d[chi] and then integrating from [chi] = [R.