pim·an·threne \pə̇ˈmanˌthrēn\noun (-s) Etymology:pimaric (in pimaric acid) + -anthrene : a crystalline aromatic tricyclic hydrocarbon (CH3)2C14H8 obtained by dehydrogenation of various bicyclic or tricyclic diterpenes and by synthesis; 1,7-dimethyl-phenanthrene