(redirected from annular ring)
Also found in: Thesaurus, Medical, Encyclopedia.
Related to annular ring: annulus


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.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


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]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(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]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.


[ˈænjʊləs] n (annules or annuli (pl)) [ˈænjʊˌlaɪ]corona circolare
Collins Italian Dictionary 1st Edition © HarperCollins Publishers 1995
References in periodicals archive ?
For example: if the design utilizes a 1.00 mm BGA pitch (which typically uses a 10 mil drilled hole on a 19 mil pad), and there is a 1 mil annular ring condition that must be followed, it reduces the hole-to-pad allowances by 2 mils (FIGURE 1).
* Drill diameters were compared to copper pad sizes to ensure sufficient annular ring for minimum acceptability.
An established dissolution hierarchy confirmed that the knee location has the highest dissolution rate, followed (in order) by the annular ring (or pad) geometries and the inner barrel wall (Figure 1).
The mount reveals important quality attributes in cross-section: delamination, voids, separation, smear and etchback, misregistration/eccentricity, (annular ring, breakout, etc).
Insufficient annular ring. Annular ring is the donut ("annulus") created when your drill pierces a copper layer.
Since you cannot have one photo-tool for each individual panel, the next best solution is to use the minimal number of photo-tools for the solder mask process, and still keep the design specification on the annular ring.
For a panel that requires an annular ring of 50 or 75 pm, most of the design tolerance might be exhausted from a single production step.
Finding mask-to-trace problems in your CAD system is difficult, because few (if any) CAD systems offer more than a basic annular ring check when it comes to soldermask data.