Belgium
frigolite
Meaning
polystyrene foam
Elsewhere
polystyrène expansé
Explanation
Standard French has the mouthful polystyrène expansé. In Belgium the white stuff in the box is frigolite, after a trademark.
Example
Il a calé les verres dans des morceaux de frigolite avant l’envoi.
He wedged the glasses in bits of polystyrene foam before sending them off.
Origin
From the registered trademark Frigolith, by antonomasia.
Source