polystyrene

noun

poly·​sty·​rene ˌpä-lē-ˈstī-ˌrēn How to pronounce polystyrene (audio)
: a polymer of styrene
especially : a rigid transparent thermoplastic that has good physical and electrical insulating properties and is used especially in molded products, foams, and sheet materials

Examples of polystyrene in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The technique usually relies on hollow glass spheres, polystyrene beads, aluminum flakes, or synthetic granules with special optical coatings to enhance the reflection of light. Ashley Belanger, ArsTechnica, 22 Aug. 2025 The law also banned polystyrene food containers like cups, plates and clamshell boxes, commonly known as Styrofoam, statewide, effective Jan. 1 of this year. Paul Rogers, Mercury News, 19 Aug. 2025 In 2023, an engineering company dug a series of trenches and boreholes up to 16 feet deep, unearthing a jumble of waste, including tires, plastic bags, timber, polystyrene and canisters. Laura Paddison, CNN Money, 15 Aug. 2025 Dylan sunk his hand down in the polystyrene. Literary Hub, 13 Aug. 2025 See All Example Sentences for polystyrene

Word History

First Known Use

1927, in the meaning defined above

Time Traveler
The first known use of polystyrene was in 1927

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Cite this Entry

“Polystyrene.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polystyrene. Accessed 9 Sep. 2025.

Kids Definition

polystyrene

noun
poly·​sty·​rene ˌpäl-i-ˈstī(ə)r-ˌēn How to pronounce polystyrene (audio)
: a stiff transparent plastic used chiefly in molded products, foams, and sheet materials

Medical Definition

polystyrene

noun
poly·​sty·​rene ˌpäl-i-ˈstī(ə)r-ˌēn How to pronounce polystyrene (audio)
: a polymer of styrene
especially : a rigid transparent thermoplastic that has good physical and electrical insulating properties and is used especially in molded products, foams, and sheet materials

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