ray
1 Americannoun
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a narrow beam of light.
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a gleam or slight manifestation.
a ray of hope.
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a raylike line or stretch of something.
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light or radiance.
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a line of sight.
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Physics, Optics.
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any of the lines or streams in which light appears to radiate from a luminous body.
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the straight line normal to the wave front in the propagation of radiant energy.
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a stream of material particles all moving in the same straight line.
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Mathematics.
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one of a system of straight lines emanating from a point.
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Also called half-line. the part of a straight line considered as originating at a point on the line and as extending in one direction from that point.
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any of a system of parts radially arranged.
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Zoology.
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one of the branches or arms of a starfish or other radiate animal.
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one of the bony or cartilaginous rods in the fin of a fish.
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Botany.
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one of the branches of an umbel.
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(in certain composite plants) the marginal part of the flower head.
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Astronomy. one of many long, bright streaks radiating from some of the large lunar craters.
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a prominent upright projection from the circlet of a crown or coronet, having a pointed or ornamented termination.
verb (used without object)
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to emit rays.
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to issue in rays.
verb (used with object)
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to send forth in rays.
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to throw rays upon; irradiate.
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to subject to the action of rays, as in radiotherapy.
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Informal. to make a radiograph of; x-ray.
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to furnish with rays or radiating lines.
idioms
noun
noun
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John, 1627?–1705, English naturalist.
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Man 1890–1976, U.S. painter and photographer.
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Satyajit 1921–92, Indian film director.
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Cape, a promontory at the SW extremity of Newfoundland, Canada, on the Cabot Strait, at the entrance of the Gulf of St. Lawrence.
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a male given name, form of Raymond.
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Also Raye a female given name, form of Rachel.
noun
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a narrow beam of light; gleam
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a slight indication, esp of something anticipated or hoped for
a ray of solace
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maths a straight line extending from a point
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a thin beam of electromagnetic radiation or particles
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any of the bony or cartilaginous spines of the fin of a fish that form the support for the soft part of the fin
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any of the arms or branches of a starfish or other radiate animal
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astronomy any of a number of bright streaks that radiate from the youngest lunar craters, such as Tycho; they are composed of crater ejecta not yet darkened, and extend considerable distances
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botany any strand of tissue that runs radially through the vascular tissue of some higher plants See medullary ray
verb
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(of an object) to emit (light) in rays or (of light) to issue in the form of rays
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(intr) (of lines, etc) to extend in rays or on radiating paths
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(tr) to adorn (an ornament, etc) with rays or radiating lines
noun
noun
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John . 1627–1705, English naturalist. He originated natural botanical classification and the division of flowering plants into monocotyledons and dicotyledons
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Man , real name Emmanuel Rudnitsky . 1890–1976, US surrealist photographer
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Satyajit (ˈsætjədʒɪt). 1921–92, Indian film director, noted for his Apu trilogy (1955–59)
noun
noun
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A thin line or narrow beam of light or other radiation.
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A geometric figure consisting of the part of a line that is on one side of a point on the line.
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See ray flower
Related Words
See gleam.
Other Word Forms
- raylike adjective
Etymology
Origin of ray1
First recorded in 1350–1400; Middle English rai, raie, raye, from Old French rai “beam of light; spoke of a wheel,” from Latin radius radius
Origin of ray2
First recorded in 1275–1325; Middle English rai(e), raye, (from Old French rai ) or directly from Latin raia
Explanation
A ray is a beam of light or radiation. Even on cloudy days, you sometimes see a ray of sunlight shine through the clouds. In physics, a ray is a line or column of light, heat, or electromagnetic radiation (like an x-ray), while in math a ray is a line that passes through a specific point. A marine biologist would define a ray as a big fish that's related to sharks and has a wide, flat body and a long tail. The root of the first two kinds of rays is the Latin word radius, "spoke" or "staff."
Vocabulary lists containing ray
Geometry - Introductory
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Geometry - Middle School
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Geometry - High School
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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.
There’s a ray gun that transforms its targets into babies.
From The Wall Street Journal • Mar. 31, 2026
The Gulf of Mexico is home to at least 19 other threatened and endangered species including various types of turtles, the giant manta ray and mountainous star coral.
From BBC • Mar. 31, 2026
"Lera was a ray of sunshine. She loved Odesa, Ukrainian culture, the opera," she said, using Valeria's diminutive name.
From Barron's • Feb. 22, 2026
“My mom was a ray of light, sunshine manifested,” said Goodarzi, 25.
From Los Angeles Times • Jan. 26, 2026
The small attic window makes a ray of light across the floor.
From "Ninth Ward" by Jewell Parker Rhodes
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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.