polystyrene

noun

poly·​sty·​rene ˌpä-lē-ˈstī-ˌrēn 

: 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

Other companies and trade groups that manufacture plastics that are banned in California — such as Dart, which produces polystyrene, and plastic bag manufacturers such as Amcor — support the bill. —Susanne Rust follow, Los Angeles Times, 17 Jan. 2026

The disaster has raised questions about bid-rigging and corruption, as well as negligence by government officials, who have cited substandard mesh netting, polystyrene boards that were sealed to the windows and fire alarm failures as major factors in the fire’s start and rapid spread. —Jennifer Jett, NBC news, 16 Jan. 2026

The initial dome would have an 18,600-square-foot precast support building, and the dome, which would have polystyrene fabric for the roof, would be 75 feet at its highest point, according to plans. —Addison Wright, Chicago Tribune, 9 Jan. 2026

Kauai has banned the sale, rental, and distribution of disposable polystyrene foam bodyboards. —Kathleen Wong, USA Today, 12 Dec. 2025

Word History

First Known Use

1927, in the meaning defined above

Rhymes for polystyrene

• acetylene
• adenosine
• amphetamine
• anthropocene
• antipyrine
• apomorphine
• apoprotein
• aquamarine
• arsphenamine
• azobenzene
• buprenorphine
• chlorobenzene

Kids Definition

polystyrene

noun

poly·​sty·​rene ˌpäl-i-ˈstī(ə)r-ˌēn 

: 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 

: 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