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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 ?
The lower plug forms a base for the column and slurry is uncontaminated when it enters the annulus.
The Cardioband Mitral Reconstruction System enables surgical-like repair of the mitral valve annulus via a transfemoral, transseptal delivery system, allowing for real-time adjustment on a beating heart.
Centek is launching its Inter Casing Centraliser Sub (ICCS), designed to be run as part of a tight tolerance casing string in deepwater, ultra-narrow annulus applications.
Therefore, can allow a vacuum in the annulus for insulation.
We used Cating's (1953) definition of annuli on scales, although we did so with disregard for their position in relation to the location of the transverse grooves because the number of transverse grooves within each annulus as outlined by Cating (1953) was discredited by Duffy et al.
Primus Line has introduced an innovative technology for the trenchless rehabilitation of pressure pipelines for the water, and oil and gas using the long pipe lining with an annulus method.
The disc joint is composed of three major parts: cartilaginous vertebral endplates that cap the bodies of the vertebrae, a fibrous annulus fibrosus that is located circumferentially between the vertebral bodies, and a thick gel-like nucleus pulposus in the center bounded by the fibers of the annulus fibrosus.
Hussain and Sharif [32] followed the same general non-orthogonal, boundary-fitted curvilinear coordinates approach to conduct a similar study; however, they compared their numerical solutions with available analytical solutions of the axial velocity distribution in a concentric annulus.
There are several techniques for estimating length-at-age from otoliths including 1) direct observed counts of annual increments; 2) age adjustment based on a categorization of otolith margins; 3) age adjustment based on known periods of spawning and annuli formation; 4) back-calculation to all annuli, and 5) back-calculation to the last annulus only.
According to this scenario, Earth and Venus formed within one particularly thick band, or annulus, in the inner solar system.
LSI research also suggests that new technologies such as annulus repair and nucleus repair/replacement could begin to limit the growth of artificial discs toward the end of the forecast period.
2005) studied heat transfer characteristics of PCM in a vertical annulus and developed empirical correlations involving Nusselt number, Rayleigh number, Steffan number, and Fourier number.