expanded polystyrene
noun /ɪkˌspændɪd ˌpɒliˈstaɪriːn/
/ɪkˌspændɪd ˌpɑːliˈstaɪriːn/
(also Styrofoam™ especially in North American English)
[uncountable]- a form of polystyrene used for protecting objects in packages and for stopping heat, noise, etc. from escaping