Pronunciation: (tûr'pēn), [key]
1. (originally) any of a class of monocyclic hydrocarbons of the formula C10H16, obtained from plants.
2. 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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.