annulus
Americannoun
-
a ring; a ringlike part, band, or space.
-
Geometry. the space between two concentric circles on a plane.
-
the veil remnant on a mushroom stalk.
-
a growth ring, as on the cross section of a tree trunk, that can be used to estimate age.
noun
-
the area between two concentric circles
-
a ring-shaped part, figure, or space
-
A ringlike figure, part, structure, or marking, such as a growth ring on the scale of a fish.
-
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.
-
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.
-
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:
It's called an annular eclipse because just a thin ring, or annulus, of light remains visible.
From BBC ● Oct. 10, 2023
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
Plant in natural position just after rupture of veil, showing tendency to double annulus on the stem.
From Studies of American Fungi. Mushrooms, Edible, Poisonous, etc. by Atkinson, George Francis
Aging white-tailed deer by annuli in the cementum of the first incisor.
From Ecological Studies of the Timber Wolf in Northeastern Minnesota by Frenzel, L. D.
In some the general hue is orange brown with obscure annuli; the arrangement of the hair is distichous or in two rows.
From Natural History of the Mammalia of India and Ceylon by Sterndale, Robert Armitage
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 Spencer, Herbert
Westwood's figure shows eight annuli to the club.
From Scientific American Supplement, No. 648, June 2, 1888. by Various
The ring distinguished the free-born from the servile, who, however, sometimes obtained the jus annuli, or privilege of the ring.
From Notes and Queries, No. 209, October 29 1853 A Medium of Inter-communication for Literary Men, Artists, Antiquaries, Geneologists, etc. by Various
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.
