What does "styrofoam" mean?

Expanded polystyrene foam, such as is used in cups and packaging.

What is a synonym for "styrofoam"?

Common synonyms include: acrylic, eps, extruded polystyrene foam, plastic, polystyrene foam, xps.

Pronounced //ˈstaɪ.ɹə.fəʊm//.

/ˈstaɪ.ɹə.fəʊm/ noun

noun ·Rare ·Advanced level

Noun

1
Expanded polystyrene foam, such as is used in cups and packaging. countable, uncountable
"A while ago I read your column concerning the effects of hot tea on styrofoam cups."
2
a light resilient foam of polystyrene wordnet

"Tom was drinking coffee out of a Styrofoam cup."

Genericized trademark of Styrofoam, from -styr- (from polystyrene) + -o- + foam.