noun, often attributive
\ ˈglas How to pronounce glass (audio) , 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
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 How to pronounce Glass (audio) \

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 How to pronounce glassful (audio) \ noun
glassless \ ˈglas-​ləs How to pronounce glassless (audio) \ adjective

Synonyms for glass

Synonyms: Noun

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Examples of glass in a Sentence

Noun 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 Most of the light travels straight through the clear, hair-thin stretch of glass. Wired, "Scientists Spot an Undersea Fault Using Fiber-Optic Cables," 28 Nov. 2019 As the nation grieves, the game is postponed a week, and Oregon learns of more bad news: Mel Renfro has accidentally cut his wrist on a piece of glass in his apartment and is out for the remainder of the season. oregonlive, "Civil War football history: The Oregon Ducks and Oregon State Beavers’ 122 meetings, game by game," 25 Nov. 2019 Expanses of glass that elide the interior with the natural surroundings. Christopher Benfey, Harper's magazine, "Burning Down the House," 25 Nov. 2019 The Super Hornet’s center cockpit display is made with a type of glass that is now obsolete, according to the report. Justin Rohrlich, Quartz, "The US Navy doesn’t have enough spare parts to keep its fighter jets in the air," 23 Nov. 2019 Then last month, to much fanfare, the company opened its 320,000-square-foot flagship women's store, whose facade is covered with five stories of wavy glass. Clare Duffy, CNN, "Brick and mortar stores are hurting many retailers, but Nordstrom is pushing them as key to the company's future," 21 Nov. 2019 Among the changes was the fact that visitors were not allowed physical contact with Joe, meaning that his daughters — Gia, 18, Gabriella, 15, Milania, 13, and Audriana, 10 — would all have to talk to their father from behind a panel of glass. Dave Quinn,, "RHONJ's Teresa Giudice's Dad Slams Joe for Not Becoming a U.S. Citizen: 'He Gotta Blame Himself'," 20 Nov. 2019 Teachers have pooled money to buy a student a pair of glasses or replace some clothes after a fire, Smejkal said. Ashley Mcbride,, "More high-poverty schools in San Antonio win ‘gold ribbons’," 17 Nov. 2019 From the first moment a shovel turned the earth for the construction of U.S. Bank Stadium, bird activists worried that its monstrous slabs of glass would kill birds. Joe Soucheray, Twin Cities, "Soucheray: For that kind of money, you might expect more bird deaths," 16 Nov. 2019 Recent Examples on the Web: Verb Jennifer Colliau’s brainchild is on-trend and forward-thinking with canned cocktails, juices clarified via centrifuge and a glassed-in prep area that would be at home at either Din Tai Fung or Jurassic Park. San Francisco Chronicle, "Why bar food in the Bay Area has never been better," 8 Nov. 2019 The property has many of its historic features, including pegged Northern English Brown oak floors and a glassed-in sun room. Nancy Sarnoff, Houston Chronicle, "Prominent Houston couple buys George R. Brown house in River Oaks," 2 Oct. 2019 Early morning sun streamed through a stain-glassed window. Los Angeles Times, "In El Paso and now Dayton, the familiar fallout of a mass shooting repeats again," 4 Aug. 2019 But here, the kitchen is entrusted to her longtime collaborator, chef Rustle Biehn, and Garaventa can step behind the glassed-in corner that is now her whole-animal, ethically focused butcher shop. Fortune, "Seattle’s Coolest New Restaurants Break the Mold," 8 Sep. 2019 Chefs tend the flames and the skewers behind a glassed-in grill; this is a fine place to splurge on pricier cuts of meat such as rack of lamb kebab. Los Angeles Times, "Two food writers eat at all the Persian restaurants in SoCal (OK, 18 of them)," 6 Aug. 2019 Adjacent to the biergarten below Fadensonnen, the glassed-in space looks from the outside like a food lab or a Mac store. Christina Tkacik,, "Larder brings Chez Panisse-style to Old Goucher," 24 July 2019 As is growing more common in high-end residential buildings, the gym is lavishly appointed with the latest equipment and occupies its own glassed-in building on the plaza instead of being tucked in a windowless corner. Los Angeles Times, "Los Angeles apartment owners race to add luxury amenities," 11 Aug. 2019 In addition to the glassed-in dining room, Waterfront Restaurant also offers patios overlooking the pristine bay of Green Bay. Travel Wisconsin, Milwaukee Journal Sentinel, "Where to find the best outdoor dining with a waterfront view in Wisconsin," 14 July 2019

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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Time Traveler for glass

Time Traveler

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

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Statistics for glass

Last Updated

5 Dec 2019

Cite this Entry

“Glass.” The Dictionary, Merriam-Webster Inc., Accessed 12 December 2019.

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More Definitions for glass


How to pronounce Glass (audio)

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 How to pronounce glass (audio) \

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 How to pronounce glass (audio) \

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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More from Merriam-Webster on glass

Thesaurus: All synonyms and antonyms for glass

Rhyming Dictionary: Words that rhyme with glass

Spanish Central: Translation of glass

Nglish: Translation of glass for Spanish Speakers

Britannica English: Translation of glass for Arabic Speakers Encyclopedia article about glass

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 period of high artistic development

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