Aromatherapy articles and recipes can often contain many terminologies that may be confusing for someone new to the subject. Here are some definitions of commonly used terms in aromatherapy.
Absolute: a highly concentrated semi-solid or solid aromatic material, usually obtained by alcohol extraction from the concrete.
Adulteration: any material added to a pure, genuine essential oil which modifies its original composition or aroma.
Analgesic: an agent that reduces pain.
Anaphrodisiac: reduces sexual desire.
Antiseptic: an agent that inhibits the development of microbes.
Antiviral: an agent that prevents the growth of viruses.
Aphrodisiac: increases sexual desire.
Aromatic: a substance with a strong aroma or smell.
Astringent: causes the contraction of skin cells and body tissues.
Carminative: settles the digestive system and relieves flatulence.
Carrier oil: a vegetable oil used to dilute pure essential oils for application to the skin.
Chemotype: plants of the same botanical class which appear identical externally but have a variation in their chemical constituents, due to different climatic, altitude or soil conditions.
Cicatrisant: promotes healing by the formation of scar tissue.
Concrete: a concentrated, waxy, semi-solid or solid perfume material derived from plant material, usually by solvent extraction.
Depurative: an agent that detoxifies and helps combat impurity in the blood and organs.
Diuretic: an agent that promotes urination.
Emmenagogue: assists menstruation.
Emollient: softens and soothes the skin.
Essential oil: a volatile and aromatic liquid or semi-solid obtained from flowers, plants, herbs, leaves, fruits, woods and gums by steam distillation, expression or other methods of extraction.
Expectorant: promotes the removal of mucous from the respiratory system.
Expression: a method of extraction specific to citrus essential oils, carried out by mechanically pressing the fruit rind to release the oil.
Fixed oil: a fatty, non-volatile vegetable oil.
Hydrosol: a floral water recovered from the steam distillation process that contains most of water soluble molecules from the plant that did not filter into the essential oil.
Infusion: a herbal remedy prepared by saturating plant material in vegetable oil or water.
Limbic system: parts of the forebrain concerned with various aspects of emotion, behaviour, learning and memory.
Lymphatic system: a network of tissues and organs that help to remove toxins and waste from the body.
Maceration: a simple form of solvent extraction, involving the submersion of flowers in hot oil until the essential oil dissolves.
Olfaction: the sense of smell.
Photo-toxicity: a sensitising reaction on the skin when exposed to ultra-violet light due to a naturally occurring component in an essential oil.
Phytotherapy: the treatment of disease by plants.
Rectification: the process of re-distillation applied to some essential oils to remove unwanted constituents.
Resin: a solid or semi-solid substance of vegetable origin exuded from plants and trees such as pine, frankincense and myrrh.
Resinoid: a material prepared from natural resinous matter such as gum resins and balsams by solvent extraction.
Rubefacient: an agent that is warming and increases blood flow.
Solvent extraction: a form of essential oil extraction that uses solvents such as hexane, ethanol or methanol.
Steam distillation: the most common method of essential oil extraction, carried out by heating plant material to produce a vapour, which is then condensed into an oil and water solution before being separated.
Synergy: the effect of two or more agents working together harmoniously to produce an effect that is greater than the sum of its separate parts.
Tincture: a herbal remedy or perfumery material prepared in a base of alcohol.