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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 ?
Research gathered by Expro suggests 19% of the world's gas wells suffer from a degree of leakage while a common location for a well leak (loss of barrier) can typically be found in the annulus between the casing strings.
The maximum stresses on the annulus fibrosus at the upper adjacent level ranged from 0.21 to 0.57 MPa (mean [+ or -] SD: 0.28 [+ or -]0.11 MPa).
Designed with an artificial viscoelastic nucleus and fiber annulus that mimics the anatomic structure of a natural disc, the M6-C device is the only artificial cervical disc available in the U.S.
The incision was continued across the stenotic part in case of a proximal narrowing when the incision was made through the pulmonary valvular annulus, an attempt was made to preserve the cusp by making the incision through the cusp.
The DTFR method is distinguished from other drilling methods by the way the drill cuttings are returned to the surface through the drill string, whereas with conventional mud or air operations the cuttings are returned up the annulus.
It is used for high-risk patients with functional mitral regurgitation, a disease that causes the heart's left ventricle to become enlarged and the valve opening, or annulus, to stretch.
This large and currently underserved patient population could benefit from a fully-percutaneous transcatheter procedure that can repair the dilated mitral annulus and reduce regurgitation without undergoing surgery.
Nucleus pulposus and annulus fibrosus regions were identified, several regions of interest were chosen, and their ADC values were obtained.
Approximations to the zeros of a polynomial can be drawn by these methods, and these methods can become more efficient when an annulus containing all the zeros of the polynomial is provided.
"The Research and Development team at TUV Rheinland has developed a new tool that fits and enters the annulus between the surface casing and the intermediate casing," remarked Fred Gabriels, the managing director at TUV Rheinland.