- a liquid terpene, C10H16, the principal constituent of oil of turpentine, found in other essential oils: used chiefly in the manufacture of camphor.
- either of two isomeric terpenes, found in many essential oils and constituting the main part of oil of turpentine. The commonest structural isomer (α-pinene) is used in the manufacture of camphor, solvents, plastics, and insecticides. Formula: C 10 H 16
