• synonyms


or fi·ber glass

[ fahy-ber-glas, -glahs ]
/ ˈfaɪ bərˌglæs, -ˌglɑs /


a material consisting of extremely fine filaments of glass that are combined in yarn and woven into fabrics, used in masses as a thermal and acoustical insulator, or embedded in various resins to make boat hulls, fishing rods, and the like.

verb (used with object)

to cover or form with fiberglass.

verb (used without object)

to use or work with fiberglass.

Nearby words

fiber, dietary, fiberboard, fibered, fiberfill, fiberglas, fiberglass, fiberize, fiberoptic, fiberscope, fibiger, fibiger, johannes

Origin of fiberglass

An Americanism dating back to 1935–40; fiber + glass Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fiberglass

  • Buried three feet below the ground was a fiberglass box filled with human bones.

    Fake Rockefeller, Real Murder: The Case of Christian Karl Gerhartsreiter|Christine Pelisek|March 19, 2013|DAILY BEAST
  • Ethanol can wreak havoc on older boats, particularly ones with fiberglass fuel tanks.

  • “Ivan Wilzig wears a cape and has this tacky castle made out of fiberglass,” says the pal.

    Partying All the Way to Jail|Peter Davis|December 21, 2009|DAILY BEAST
  • Well, there is a bench along, in front of, a fiberglass window panel.

    Warren Commission (9 of 26): Hearings Vol. IX (of 15)|The President's Commission on the Assassination of President Kennedy

Science definitions for fiberglass


[ fībər-glăs′ ]

A material made up of very fine fibers of glass. Fiberglass is resistant to heat and fire and is used to make various products, such as building insulation and boat hulls. Because the fibers in fiberglass are capable of transmitting light around curves, fiberglass is an important component of fiber optics.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.