noun, often attributive
\ˈglas, ˈgläs\

Definition of glass 

(Entry 1 of 4)

1 : any of various amorphous materials formed from a melt by cooling to rigidity without crystallization: such as

a : a usually transparent or translucent material consisting typically of a mixture of silicates

b : a material (such as obsidian) produced by fast cooling of magma

2a : something made of glass: such as

(1) : tumbler also : glassware

(2) : mirror

(3) : barometer

(4) : hourglass

(5) : backboard sense 1

b(1) : an optical instrument or device that has one or more lenses and is designed to aid in the viewing of objects not readily seen

(2) : field glasses, binoculars usually used in plural

c glasses plural : a device used to correct defects of vision or to protect the eyes that consists typically of a pair of glass or plastic lenses and the frame by which they are held in place

called also eyeglasses, spectacles

3 : the quantity held by a glass container

5 : crystal meth specifically : a pure form of crystal meth


glassed; glassing; glasses

Definition of glass (Entry 2 of 4)

transitive verb

1a : to provide with glass : glaze sense 1

b : to enclose, case, or wall with glass the sunroom was glassed in

2 : to make glassy

3a : reflect

b : to see mirrored

4 : to look at through an optical instrument (such as a pair of binoculars)


biographical name (1)
\ˈglas \

Definition of Glass (Entry 3 of 4)

Carter 1858–1946 American statesman


biographical name (2)

Definition of Glass (Entry 4 of 4)

Philip 1937–     American composer

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Other Words from glass


glassful \ˈglas-ˌfu̇l \ noun
glassless \ˈglas-ləs \ adjective

Synonyms for glass

Synonyms: Noun

eyeglasses, specs, spectacles

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Examples of glass in a Sentence


The waiter filled our glasses with water. She drank two glasses of water. She was wearing dark glasses with thick black frames.
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Recent Examples on the Web: Noun

Raising a glass of Didyme, a dry Malvasia made with grapes grown in Capofaro’s vineyard, Vitale toasted the volcano. Howie Kahn, Smithsonian, "These Volcanic, Italian Islands Have Been Beloved by Travelers Since Homeric Times," 11 July 2018 Does the activity also work with a plastic bottle instead of a glass one? Svenja Lohner, Scientific American, "Floating with a Swim Bladder," 5 July 2018 Terzini’s other spot, the new Bondi Public Beach Bar, is the kind of place where a cheeky glass of vino at lunch usually turns into three bottles before dinner. Erin Florio, Condé Nast Traveler, "What to Do in Sydney: The Black Book," 5 July 2018 To prepare a beverage, combine 2 ounces syrup and 8 ounces sparkling or still water in a glass. San Antonio Express-News, "Recipe: Pineapple Squash drink," 3 July 2018 Stanfield: [stylist brings him a shot of whiskey in a glass] Thank you, baby. Bijan Stephen, The Verge, "What’s in your bag, Lakeith Stanfield?," 29 June 2018 When dealing with skincare concerns, these products are infinitely more effective than chugging a glass of orange juice, a sugary yet undeniably delicious beverage popular in Florida. Adam Hurly, GQ, "The Best Vitamin C Products for Having Clear, Healthy Skin," 29 June 2018 At the time, Santa Cruz police said a surveillance video showed Tichelman panicking and attempting to revive Hayes before gathering her belongings, stepping over his body to finish a glass of wine and leaving him on the yacht without seeking help. Molly Sullivan, sacbee, "Folsom prostitute convicted in death of Google exec now charged in ex-boyfriend's fatal OD," 27 June 2018 The breathtaking views in every direction pair beautifully with a signature Skyspace cocktail, a glass of California wine, or beer from a local brewery. Lisa Beebe, Los Angeles Magazine, "High Above the City Streets, OUE Skyspace Offers a Fresh Perspective on Los Angeles," 26 June 2018

Recent Examples on the Web: Verb

Sherman Samuel suggested a Pink Marble pattern from her Lulu & Georgia wallpaper collection for the more intimate glassed-in showroom, with flooring that's a vinyl decal from Atrafloor but looks like stone and brass inlay from a distance. Jessica Ritz,, "A DTLA jewelry designer's studio and showroom get a shining makeover," 26 May 2018 The stunning bathrooms combine tumbled marble, travertine, and glassed-in showers with multiple body sprays. Joan Walden,, "Property of the Week: 485 Deercliff Road, Avon," 20 Oct. 2017 The sidewalk tables were filled with couples, families filled the glassed-in terrace, old friends lined the bar. Michael Kiefer, azcentral, "Paris terrorist attacks didn't crush the spirit of the 11th Arrondissement," 10 May 2018 The Voodoo Lounge, located on the northeast wing, fuses sports bar culture and live music with trivia nights and video poker. The glassed-in patio space seats up to 56 guests. Patrick Z. Mcgavin, Daily Southtown, "Guide to outdoor dining in Chicago suburbs: Chuck's Southern Comforts Cafe in Burbank," 9 July 2018 Framery, an 8-year-old Finnish company, introduced its own napping pod at NeoCon, a variation on its glassed-in, soundproof meeting pod. The $20,000 NapQ features two cushioned chairs that transform into a bed. Robert Channick,, "Office napping climbs out from under the desk and into high-tech pods," 5 July 2018 Mike the Tiger moved through the water of his glassed-in enclosure with the elegant stealth of, well, a tiger. Lisa Gutierrez, kansascity, "Millions watch video of Mike the Tiger 'stalk' LSU visitor. Then his caretaker pounced," 21 June 2018 The interior is equally sleek and minimalist, allowing details like the decorative black and white floor tiles on the front glassed in dining space to shine. Lindsey Mcclave, The Courier-Journal, "Louisville Italian restaurant is full of potential but has work to do," 20 June 2018 Off a hallway with spacious his-and-her closets is the Travertine master bath with curved walls, a double vanity, and a glassed-in shower with dual showerheads. Joan Walden,, "Property of the Week: 22 Pasture Lane, West Simsbury," 18 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'glass.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of glass


before the 12th century, in the meaning defined at sense 1


14th century, in the meaning defined at transitive sense 1a

History and Etymology for glass


Middle English glas, from Old English glæs; akin to Old English geolu yellow — more at yellow

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Learn More about glass

Dictionary Entries near glass






glass arm

glass bell

Statistics for glass

Last Updated

10 Oct 2018

Look-up Popularity

Time Traveler for glass

The first known use of glass was before the 12th century

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More Definitions for glass



English Language Learners Definition of glass

 (Entry 1 of 2)

: a hard usually transparent material that is used for making windows and other products

: a drinking container made out of glass

: the amount held by a glass container



English Language Learners Definition of glass (Entry 2 of 2)

: to fit, protect, or enclose (something) with glass


\ˈglas \

Kids Definition of glass

1 : a hard brittle usually transparent substance commonly made from sand heated with chemicals

2 : a drinking container made of glass

3 glasses plural : a pair of glass or plastic lenses held in a frame and used to help a person see clearly or to protect the eyes

4 : the contents of a glass a glass of milk


noun, often attributive
\ˈglas \

Medical Definition of glass 

1a : an amorphous inorganic usually transparent or translucent substance consisting of a mixture of silicates or sometimes borates or phosphates formed by fusion of silica or of oxides of boron or phosphorus with a flux and a stabilizer into a mass that cools to a rigid condition without crystallization

b : a substance resembling glass especially in hardness and transparency organic glasses made from plastics

2a : an optical instrument or device that has one or more lenses and is designed to aid in the viewing of objects not readily seen

b glasses plural : a device used to correct defects of vision or to protect the eyes that consists typically of a pair of glass or plastic lenses and the frame by which they are held in place

called also eyeglasses

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Comments on glass

What made you want to look up glass? Please tell us where you read or heard it (including the quote, if possible).


a state of commotion or excitement

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