fiberglass

1 of 2

noun

fi·​ber·​glass ˈfī-bər-ˌglas 

1

: glass in fibrous form used in making various products (such as glass wool for insulation)

2

: a composite structural material of plastic and fiberglass

fiberglass

2 of 2

verb

fiberglassed; fiberglassing; fiberglasses

transitive verb

: to protect or repair by applying fiberglass

Examples of fiberglass in a Sentence

Recent Examples on the Web

Noun

But nothing hitting Earth is thankfully as large as a 25-foot-high fiberglass doughnut. — Jaclyn Cosgrove, Los Angeles Times, 30 July 2026

In 1986, a fiberglass sculpture of a shark plunging headfirst into the roof of an ordinary-looking row house in the English town of Headington appeared as if out of nowhere. — Leslie Felperin, HollywoodReporter, 21 July 2026

Verb

It's compared usually to fiberglass. — Rachel Raposas, PEOPLE, 31 Mar. 2026

Baking soda shouldn't be mixed with ammonia, bleach, alcohol, or chemical cleaners due to dangerous reactions, and should be used with care on glass, leather, marble, or fiberglass to avoid damage. — Melissa Locker, Southern Living, 15 Mar. 2026

Word History

First Known Use

Noun

1937, in the meaning defined at sense 1

Verb

1967, in the meaning defined above

Rhymes for fiberglass

• fibreglass
• hourglass
• isinglass
• lemongrass
• martinmas
• orchardgrass
• overpass
• plexiglas
• plexiglass
• sassafras
• superclass
• underclass

Kids Definition

fiberglass

noun

fi·​ber·​glass

-ˌglas

: glass in the form of fibers used in making various products (as yarn, insulation, or boats)