- See under terpene(def 2).
- (originally) any of a class of monocyclic hydrocarbons of the formula C10H16, obtained from plants.
- this class or any of its oxygenated derivatives, any hydrocarbon from the same source having the formula C5H8 (hemiterpene), the formula C10H16 with an aliphatic structure (acyclic terpene) or two-ringed structure (bicyclic terpene), the formula C15H24 (sesquiterpene), etc., and any of their oxygenated derivatives.
- any one of a class of unsaturated hydrocarbons, such as the carotenes, that are found in the essential oils of many plants. Their molecules contain isoprene units and have the general formula (C 5 H 8) n
- Any of various unsaturated hydrocarbons in essential oils and certain resins of plants and used in organic syntheses.
- Any of a class of hydrocarbons consisting of two or more isoprene (C5H8) units joined together. Simple terpenes are found in the essential oils and resins of plants such as conifers. Turpentine, for example, is such an oil. More complex terpenes include vitamin A, carotenoid pigments (such as lycopene), squalene, and rubber. Terpenes are used in organic synthesis.