glass wool

American  

noun

1. spun glass similar to wool, used for insulation, filters, etc.

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glass wool British  

noun

1. fine spun glass massed into a wool-like bulk, used in insulation, filtering, etc

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Etymology

Origin of glass wool

First recorded in 1875–80

Example Sentences

Mid and East Antrim Borough Council said building regulations introduced in the 1970s led to the widespread use of safe insulation materials like glass, wool and fibreglass.

From BBC • Mar. 25, 2026

McKinley favored high tariffs on goods like steel, iron, glass, wool, sugar and beans as a way to protect and expand American industry.

From New York Times • Dec. 6, 2018

The Germans had stripped the steel works, machine shops, locomotive factories, glass, wool, linen, silk, even macaroni factories of their machinery and left the buildings charred and gutted.

From Time Magazine Archive

The glass house also contains another important Owens-Illinois product: spun glass, or glass wool, woven into thick mats and used as insulator of heat and sound.

From Time Magazine Archive

Filter through "glass wool" or quick filtering paper.

From A Text-book of Assaying: For the Use of Those Connected with Mines. by Beringer, Cornelius