1. Any of a large class of materials with highly variable mechanical and optical properties that solidify from the molten state without crystallization, are typically made by silicates fusing with boric oxide, aluminum oxide, or phosphorus pentoxide, are generally hard, brittle, and transparent or translucent, and are considered to be supercooled liquids rather than true solids.
2. Something made of glass or other transparent or translucent material, especially:
a. A drinking vessel.
b. A mirror.
c. A barometer.
d. A window or windowpane.
e. The series of transparent plastic sheets that are secured vertically above the boards in many ice rinks.
a. glasses A pair of lenses mounted in a light frame, used to correct faulty vision or protect the eyes.
b. often glasses A binocular or field glass.
c. A device, such as a monocle or spyglass, containing a lens or lenses and used as an aid to vision.
4. The quantity contained by a drinking vessel; a glassful.
5. Objects made of glass; glassware.
1. Made or consisting of glass.
2. Fitted with panes of glass; glazed.
v. glassed, glass·ing, glass·es
a. To enclose or encase with glass.
b. To put into a glass container.
c. To provide with glass or glass parts.
2. To make glassy; glaze.
a. To see reflected, as in a mirror.
b. To reflect.
4. To scan (a tract of land or forest, for example) with an optical instrument.
1. To become glassy.
2. To use an optical instrument, as in looking for game.
[Middle English glas, from Old English glæs; see ghel-2 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.