松烯
Terpene \Ter"pene\, n. [See {Turpentine}.] (Chem.) Any one of a series of isomeric hydrocarbons of pleasant aromatic odor, occurring especially in coniferous plants and represented by oil of turpentine, but including also certain hydrocarbons found in some essential oils.
terpene n : an unsaturated hydrocarbon obtained from plants