annulus
Americannoun
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annuli,
plural
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annuluses
plural
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a ring; a ringlike part, band, or space.
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Geometry. the space between two concentric circles on a plane.
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the veil remnant on a mushroom stalk.
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a growth ring, as on the cross section of a tree trunk, that can be used to estimate age.
noun
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the area between two concentric circles
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a ring-shaped part, figure, or space
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annuluses
plural
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A ringlike figure, part, structure, or marking, such as a growth ring on the scale of a fish.
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A ring or group of specialized cells around the sporangia of many ferns. By changing shape in response to variations in humidity, it breaks open the sporangium and then releases the spores with a whipping motion.
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The ringlike remains of a membrane (called a veil), found around the stipes of certain basidiomycete mushrooms. The presence or absence of an annulus is often used to identify the species of an individual mushroom.
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The figure bounded by and containing the area between two concentric circles.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of annulus
1555–65; < Latin, variant of ānulus, equivalent to ān ( us ) ring + -ulus -ule
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Shells have always played an important role in Mauritian culture - the Monetaria annulus, commonly known as gold ring cowrie, is a gift of love or luck.
From BBC ● Dec. 28, 2021
The circular annulus sector R bounded by the circles 4x2 + 4y2 = 1 and 9x2 + 9y2 = 64, the line x = y 3, and the y-axis is shown in the following figure.
From Textbooks ● Mar. 30, 2016
The red primer annulus makes me lean towards Iran, but this example could quite easily have come from either country.
From New York Times ● Nov. 7, 2012
Its tubercles and soft tissues were inflamed, and the annulus fibrosus of its disks was the color of bad teeth.
From The New Yorker ● Feb. 28, 2011
A much smaller slab, smaller in diameter and in thickness than the other, is cut into an annulus or ring; and this ring is turned by tools on both edges and both sides.
From The Catholic World; Volume I, Issues 1-6 A Monthly Eclectic Magazine by E. Rameur
Westwood's figure shows eight annuli to the club.
From Scientific American Supplement, No. 648, June 2, 1888. by Various
The jus annuli aurei, or right of wearing a gold ring, originally a military distinction, became a senatorial privilege, which was afterwards extended to the knights and gradually to other classes.
From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 4 "Coquelin" to "Costume" by Various
As remarked, the prevalent number of annuli to a segment is three in the Rhynchobdellidae.
From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7 "Cerargyrite" to "Charing Cross" by Various
In the Gnathobdellidae the prevailing number of annuli to a segment is five; but here again the number is often increased, and Trocheta has no less than eleven.
From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7 "Cerargyrite" to "Charing Cross" by Various
It looks as though these partially-formed annuli must be prevented by their acquired motions from approaching even very near to the still-irregular body they surround.
From Essays: Scientific, Political, & Speculative, Vol. I by Herbert Spencer
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
