silphiperfolene

Noun

 * 1)  Any of a group of tricyclic sesquiterpenoid hydrocarbons (typically (3S,3aR,5aR,8S,8aS)-3,5a,7,8-tetramethyl-2,3,3a,4,5,8-hexahydro-1H-cyclopenta[h]pentalene)