either of two colourless liquid hydrocarbons, -pinene and -pinene, occurring as major components of the essential oil of pine trees and used as a ... Found on http://www.britannica.com/eb/a-z/p/69
Pinene is a terpene colourless liquid which smells like turpentine and occurs in pine trees and the essential oils of eucalyptus, lemon and thyme. Found on http://www.probertencyclopaedia.com/browse/GP.HTM