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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 predictions for laminar flow have been compared to literature data containing experimental data and predictions of numerical simulators which model fully flow in annuli.
The cementum annuli method requires that you remove the two center teeth from the front of the lower jaw.
I just want to let you know that my company, Wildlife Analytical Laboratories, provides cementum annuli aging services.
65 condenser, a disc diaphragm with five annuli, cord hangers, color-coded coaxial focusing knobs, a lighted on/off power switch, an "Ultra Lite" illuminator and a one-piece field condenser housing/base.
These results demonstrated that growth rate determinations from annuli measurements are unreliable unless environmental conditions remain static.
Deformation of the tracer line (which is represented by 1000 points) in the thin and thick annuli after 5, 10, 15, and 20 rotations is calculated for [[Omega].
The valve delivers excellent hemodynamic performance with low pressure gradients, large effective orifice areas and left ventricular mass regression also in patients with small annuli.
The long-term gravitational interaction between such annuli is similar to the Coulomb interaction between axisymmetric molecules constituting a liquid crystal.
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.
For both the horizontal annuli of Type A and Type B, it is observed that the effects of heating both the surfaces is the same as the heating of inside surface or the outside surface separately until there is an interaction between the two melt-zone.
H, "Flow of Non-Newtonian Fluid Through Eccentric Annuli With Carrying Capacity Design for Directional Well.
Abstract--We verified the age and growth of swordfish (Xiphias gladius) by comparing ages determined from annuli in fin ray sections with daily growth increments in otoliths.