Volatile oils that give cannabis plants their characteristic odor or flavor – contained in the secreted resins of plants.
Essential oils, volatile oils, ethereal oils or aetheroleum are types of oils composed of hydrophobic volatile organic compounds, usually in liquid form, obtained from plant material, such as oil of clove from clove. An essential oil is "essential" in the sense that the oil contains the fragrance or "essence" of that plant. The term "essential" used here does not indicate that it is nutritionally required in the diet, as with essential amino acid or essential fatty acid. A natural component of plant rinds, leaves, or bark, essential oils are fragrant if the plant is crushed or industrially extracted using a steam process.
Essential oils have diverse chemical properties and uses, such as inhalation for aromatherapy or application on skin when diluted for massage. They may be used to lessen pain or exert a cough-suppressing effect.
Many essential oils, particularly tea tree oil, may cause contact dermatitis. Improper use of essential oils may cause harm, including allergic reactions or other adverse effects if ingested, particularly by children.