An unsaturated hydrocarbon obtained from plants WordNet 3.0 & Open English WordNet

Terpenes are a class of natural products consisting of compounds with the formula n for n ≥ 2. Wikipedia

Any unsaturated hydrocarbon with structure that is a result of the assembling of five-carbon isoprene units Wikidata

A very large class of naturally occurring and synthetic organic compounds formally derived from the hydrocarbon isoprene; they include many volatile compounds used in perfume and food flavours, turpentine, the steroids, the carotene pigments and rubber. Wiktionary

Organic compound. Wiktionary (translation)