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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 ?
In addition, fMRI revealed ADC values of corresponding areas in nuclei pulposi and annuli fibrosi of the same segment of intervertebral discs in four groups of SD rats to also decrease as the rats aged.
In most elasmobranch studies, sagittally sectioned vertebrae are selected as the primary age structure (Cailliet and Goldman, 2004), although clarity of annuli within vertebrae is largely species-specific.
The youngest clams in New Jersey and Delmarva formed annuli about a month earlier than the older age classes.
Dorsal-fin spines had well-defined annuli, but vascularization near the core prevented consistent identification of the first annulus and led to biased ages.
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.
PIP is a special type of fabricated pipeline with two concentric pipes with insulating material contained within the annuli.
The nucleus in our sampling represents the initial 4-6 months in growth which encompasses halibut metamorphosis [12]; in contrast, the 5th and 8th annuli represent the time of reduced migration and onset of halibut maturation.
Our objective was to compare aging techniques (gum-line measurement and cementum annuli analysis) for Cougars (Puma concolor) using harvest data collected during 2006-2010 in Oregon.
Furthermore, crayfish antennular flagella grow continuously throughout an animal's lifespan by adding annuli and sensilla at their base; this means that aesthetascs near the flagellum tip are the oldest, and in adult individuals a proportion of them, along with the distal annuli, are shed at each molt (Sandeman and Sandeman, 1996).
Both sets of tissues were processed, sectioned and stained with Hemotoxyllin / Eosin, to observe the architecture of annuli fibrosis and nuclei pulposus parts of disc and the micro-vessels under light microscope.
The grout bag acts as a support for the mudmat and as a seal to form a plug for the leg pile annuli during the next stage.