poly·sty·rene .päl-i-'stī(ə)r-.ēn n a polymer of styrene esp a rigid transparent thermoplastic that has good physical and electrical insulating properties and is used esp. in molded products, foams, and sheet materials
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poly·sty·rene (pol″e-stiґrēn) a hard, transparent, thermoplastic synthetic resin produced by the polymerization of styrene; used in the construction of denture bases.Medical dictionary. 2011.