hard, colorless thermoplastic resin, 1922, so called because it is a polymer of styrene.
Entries linking to polystyrene
polymer n.
a substance built from a large number of simple molecules of the same kind, 1855, probably from German Polymere (Berzelius, 1830), from Greek polymeres "having many parts," from polys "many" (from PIE root *pele- (1) "to fill") + meros "part" (from PIE root *(s)mer- (2) "to get a share of something").
styrene n.
colorless hydrocarbon, 1885, from Styrax, name of a genus of trees (the chemical is found in their resin), 1786, from Latin styrax, from Greek styrax, the tree name, of Semitic origin (compare Hebrew tsori "terebinth resin"). Form influenced by Greek styrax "shaft of a lance."
Styrofoam n.
1950, trademark name (Dow Chemical Co.), from -styr- (from polystyrene) + connective -o- + foam (n.).