1. 
[syn: styrene, cinnamene, phenylethylene, vinylbenzene]
The Collaborative International Dictionary of English v.0.48:
Styrolene \Sty"ro*lene\, n. (Chem.)
   An unsaturated hydrocarbon, C8H8, obtained by the
   distillation of storax, by the decomposition of cinnamic
   acid, and by the condensation of acetylene, as a fragrant,
   aromatic, mobile liquid; -- called also phenyl ethylene,
   vinyl benzene, styrol, styrene, and cinnamene.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Cinnamene \Cin"na*mene\, n. [From Cinnamic.] (Chem.)
   Styrene (which was formerly called cinnamene because obtained
   from cinnamic acid). See Styrene.
   [1913 Webster]
WordNet (r) 3.0 (2006):
cinnamene
    n 1: a colorless oily liquid; the monomer for polystyrene [syn:
         styrene, cinnamene, phenylethylene, vinylbenzene]