Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “polystyrene”


noun [U]
/ˌpɒlɪˈstaɪriːn/ UK (US trademark Styrofoam)
a light plastic material that is wrapped around delicate objects to protect them, and around hot things to keep them hot: polystyrene packaging/polystyrene cupsPlastics and rubberWrapping, packing and loading
(Definition of polystyrene from the Cambridge Learners Dictionary © Cambridge University Press)
Browse related topics

You are looking at an entry to do with Wrapping, packing and loading, but you might be interested in these topics from the Including and excluding topic area:

Add Cambridge dictionaries to your browser to your website

Definitions of “polystyrene” in other dictionaries

Word of the Day


a large usually drinking cup, usually made of metal, with sloping sides, a handle, and sometimes a lid, mainly used for drinking beer

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More