a hard, brittle, noncrystalline, more or less transparent substance produced by fusion, usually consisting of mutually dissolved silica and silicates that also contain soda and lime, as in the ordinary variety used for windows and bottles.
any artificial or natural noncrystalline and transparent hard substance, such as fused borax, obsidian, or the like.
something made of a noncrystalline and transparent hard substance, such as a windowpane.
a tumbler or other comparatively tall, handleless drinking container.
the quantity contained within a tumbler or other tall, handleless drinking container; a glassful.
She poured two glasses of wine for herself and her guest.
Drink a glass of orange juice and you'll feel better.
a tumbler or other tall, handleless drinking container with its contents.
Hand me that glass of milk.
Also called eyeglasses. glasses, a device to compensate for impaired vision or to protect the eyes from light, dust, and the like, consisting usually of two glass or plastic lenses set in a frame that includes a nosepiece for resting on the bridge of the nose and two sidepieces extending over or around the ears (usually used withpair of ).
a mirror.
things made of glass, collectively; glassware.
They used to collect old glass.
a lens, especially one used as a magnifying glass.
a spyglass.
made of glass.
a glass tray.
furnished or fitted with panes of glass; glazed.
to fit with panes of glass.
cover with or encase in glass.
to coat or cover with fiberglass.
to glass the hull of a boat.
to scan with a spyglass or other optical instrument.
to reflect.
Trees glassed themselves in the lake.
Carter, 1858–1946, U.S. statesman.
Philip, born 1937, U.S. composer.
a hard brittle transparent or translucent noncrystalline solid, consisting of metal silicates or similar compounds. It is made from a fused mixture of oxides, such as lime, silicon dioxide, etc, and is used for making windows, mirrors, bottles, etc
( as modifier )
a glass bottle
any compound that has solidified from a molten state into a noncrystalline form
something made of glass, esp a drinking vessel, a barometer, or a mirror
Also called: glassful. the amount contained in a drinking glass
glassware collectively
See volcanic glass
See fibreglass
to cover with, enclose in, or fit with glass
informal to hit (someone) in the face with a glass or a bottle
Common sand and glass are both made primarily of silicon and oxygen, yet sand is opaque and glass is transparent. Glass owes its transparency partly to the fact that it is not a typical solid. On the molecular level, solids usually have a highly regular, three-dimensional crystalline structure; the regularities distributed throughout the solid act as mirrors that scatter incoming light. Glass, however, consists of molecules which, though relatively motionless like a typical solid, are not arranged in regular patterns and thus exhibit little scattering; light passes directly through. At a specific temperature, called the melting point, the intermolecular forces holding together the components of a typical solid can no longer maintain the regular structure, which then breaks down, and the material undergoes a phase transition from solid to liquid. The phase transition in glass, however, depends on how quickly the glass is heated (or how quickly it cools), due to its irregular solid structure.
First recorded before 900; Middle English noun glas, Old English glæs; cognate with Dutch, German Glas
Glass is the hard, transparent material that's used to make windows. While glass can be strong and sturdy, it's also brittle and can be broken easily by an errant baseball. Glass has all kinds of practical uses, from car windshields to greenhouse windows to jam jars to drinking glasses. When someone offers you a glass of water, they're referring to the vessel itself as a glass and also to amount it can hold — the glassful of liquid. The Old English source of glass is glæs, ultimately from a Proto-Indo-European root that means "to shine."
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
“Students are right to be confused,” said Matt Sigelman, president of the Burning Glass Institute, a nonprofit data lab focused on work, learning and career paths.
From MarketWatch • Jun. 22, 2026
Google is also having a second go at wearables, as that company recently said it would try again with "smart glasses" more than a decade after its notorious Google Glass flop.
From BBC • Jun. 2, 2026
Proxy advisors Glass Lewis and Institutional Shareholder Services both urged investors to vote against the move to Texas.
From Barron's • May 27, 2026
“We’re not surprised the two dominant proxy advisory firms ISS and Glass Lewis are against our redomiciliation to Texas,” the ads read.
From The Wall Street Journal • May 21, 2026
The door opened, and Mrs. Glass, a medium-stout woman in a hairnet, sidled into the bathroom.
From "Franny and Zooey" by J. D. Salinger
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.
