Common Terms

Adulterant — a substance, artificial or natural, added to an essential oil, which was not originally present in the oil at the time of distillation.

Base oil (carrier oil) — vegetable, nut or seed oils. (e.g., sweet almond, grapeseed, jojoba or coconut oil)

Diffuser — a device that disperses essential oils into an area. The three basic types are clay, candle and electric.

Dilute — adding a small amount of essential oil to a larger amount of base oil to make it safe for use on the skin.

Distillation — method used to extract essential oil from the plant. Steam distillation is the most common form of distillation.

GC/MS (Gas Chromatography/Mass Spectrometry) — a device used by analytic chemists to determine the precise make-up of a given substance. Used in Aromatherapy to determine the precise chemical constituents of an essential oil, and whether it is pure or adulterated with synthetic chemicals or other products.

Essential oil — highly aromatic substance found in specialized cells of certain plants. Technically, when this substance is in the plant, it is called an “essence.” After distillation of a single type of plant, the aromatic substance is referred to as an essential oil. Essential oils may be used by plants for protection from predators, to attract pollinators, or for other unknown uses.

Herbally infused oil — these are oils that carry the medicinal properties of certain herbs. A carrier oil is infused with the medicinal herb, the plant is strained off, and the remaining oil can be used directly on the skin.

Neat — use of an undiluted essential oil on the skin.

Notes — as in top, middle, and base notes. A type of classification system based on aroma, to identify certain oils. Generally, essential oils from citrus peels are top notes, essential oils from flowers, leaves and stems are middle notes, and essential oils from roots are base notes.

Orifice reducer — a device used to reduce the size of the opening of a bottle, making dispensing easier and more accurate.

Oxidation — when oxygen, light or heat interacts with essential oils, the essential oil begins to deteriorate over time. This can cause the essential oil to become skin irritating. It happens over the period of 1–3 years with oils high in monoterpenes, phenols and oxides, and more slowly with the other chemical families.

Phototoxic — the use of the oil makes one’s skin more prone to damage from the sun’s UV rays. Primarily the citrus oils, especially Lemon and Bergamot, as well as Angelica oil, are phototoxic oils.

Volatile — describes how quickly a substance disperses itself into the air. In Aromatherapy, top note essential oils may be referred to as “highly volatile,” meaning that they disperse quickly out of the bottle and into the air.

Definitions of Therapeutic Properties


Adaptogenic – (Medicine) acting to normalize and regulate the systems of the body: adaptogenic herbs.

Analgesic – a remedy that relieves or allays pain.

Anesthetic – an agent that causes loss of sensation with or without the loss of consciousness.

Anthelmintic – an agent that destroys or causes the expulsion of parasitic intestinal worms.

Antiarthritic – of or relating to a medicine or therapy that relieves the symptoms of arthritis.

Antibacterial – destructive to or inhibiting the growth of bacteria.

Anticarcinogenic – pertaining to a substance or device that neutralizes the effects of a cancer-causing substance.

Anticatarrhal – Efficacious against catarrh.
(catarrh) inflammation of a mucous membrane in humans or animals; especially one chronically affecting the human nose and air passages.

Anticonvulsant – preventing or alleviating convulsions.

Anticoagulant – a substance that prevents the clotting of blood.

Antidepressant – used or tending to relieve or prevent psychic depression.

Antidiabetic – acting against or preventing diabetes.

Antidiarrheal – tending to prevent or relieve diarrhea.

Antidote – a medicine or other remedy for counteracting the effects of poison, disease, etc.

Antiemetic – used or tending to prevent or check vomiting.

Antifungal – – substances that destroy Fungi by suppressing their ability to grow or reproduce.

Antihemorrhagic – any drug or agent used to prevent or control bleeding, such as thromboplastin or thrombin, either of which mediates the blood-clotting process.

Antihistamine – any of various compounds that counteract histamine in the body and that are used for treating allergic reactions (as hay fever) and cold symptoms.

Anti-Infectious – (anti-infective) capable of preventing or counteracting infection.

Anti-Inflammatory – acting to reduce certain signs of inflammation, as swelling, tenderness, fever, and pain.

Anti-Influenza – used to prevent influenza.

Antinociceptive the action or process of blocking the detection of a painful or injurious stimulus by sensory neurons

Antimicrobial – tending to destroy microbes, to prevent their multiplication or growth, or to prevent their pathogenic action.

Antimutagenic – reducing the rate of mutation.

Antineuralgic –  an agent that relieves neuralgia. (Neuralgia is defined as an intense burning or stabbing pain caused by irritation of or damage to a nerve.)

Antioxidant – an agent that inhibits oxidation; any of numerous chemical substances including certain natural body products and nutrients that can neutralize the oxidant effect of free radicals and other substances.

Antiparasitic – destroying or inhibiting the growth and reproduction of human or animal parasites.

Antiphlogistic – countering inflammation and fever.

Antiplatelet – acting against or destroying blood platelets.

Antiproliferative – used or tending to inhibit cell growth.

Antirheumatic – denoting an agent that suppresses manifestations of rheumatic disease; usually applied to anti-inflammatory agents or agents that are capable of delaying progression of the basic disease process in inflammatory arthritis.

Antiseborrheic – preventing or relieving excessive secretion of sebum; preventing or relieving seborrheic dermatitis.

Antiseptic – opposing sepsis, putrefaction, or decay; especially :  preventing or arresting the growth of microorganisms (as on living tissue).

Antispasmodic – capable of preventing or relieving spasms or convulsions.

Antistress – acting to prevent or reduce stress.

Antitoxic – counteracting toxic influences.

Antitussive – tending or having the power to act as a cough suppressant.

Anti-venomous – opposing the action of venom.

Antiviral – an agent effective against viruses.

Anxiolytic – preventing or reducing anxiety; anti-anxiety.

Aperitif – an appetite stimulant.

Aphrodisiac – promoting sexual desire or performance.

Astringent – a substance that contracts the tissues or canals of the body, thereby diminishing discharges, as of mucus or blood.


Bactericidal – Causing the death of bacteria.

Bechic – a cough suppressant.

Bronchodilatory – causing an increase in caliber of a bronchus or bronchial tube.


Calming – soothing; tranquilizing.

Calmative – Having relaxing or pacifying properties; sedative.

Cardiac – Of, near, or relating to the heart: cardiac arteries.

Cardiotonic – having a positive effect on cardiac function.

Carminative – a drug causing expulsion of gas from the stomach or bowel.

Catalyst – A substance that starts or speeds up a chemical reaction while undergoing no permanent change itself.

Cephalic – of or relating to the head.

Cholagogue – an agent that promotes an increased flow of bile.

Circulatory – of or pertaining to circulation or to the circulatory system.

Cicatrisant – promoting the healing of a wound or the formation of a cicatrix (fibrous tissue that results in a scar).

Cooling – imparting a sensation of moderate coldness or comfortable freedom from heat.

Cordial – an invigorating and stimulating medicine, food, or drink.

Cytophylactic – Relating to cytophylaxis. (Cytophylaxis – the protection of cells against cytolysis.) (cytolysis – The dissolution or destruction of a cell.)


Decongestant – an agent that relieves congestion (as of mucous membranes).

Degreaser – removes grease.

Deodorant – destroying or masking offensive odors.

Detoxification – a :  to remove a poison or toxin or the effect of such from, b:  to render (a harmful substance) harmless.

Detoxifying – To counteract or destroy the toxic properties of.

Diaphoretic – producing or increasing perspiration.

Digestive – a substance promoting digestion.

Disinfectant -to free from infection especially by destroying harmful microorganisms.

Diuretic – tending to increase the excretion of urine.


Emmenagogue – a drug or agent that induces or hastens menstrual flow.

Euphoric – a feeling of great happiness or well-being.

Expectorant – promoting or facilitating the secretion or expulsion of phlegm, mucus, or other matter from the respiratory tract.


Febrifuge – serving to reduce fever, as a medicine.

Fixative – a substance used to fix living tissue.

Fungicide – an agent that destroys fungi or inhibits their growth.


Galactogogue – any substance that increases milk secretion.

Germicidal – destructive to pathogenic microorganisms.


Haemostatic/Hemostatic – an agent that checks bleeding; especially :  one that shortens the clotting time of blood.

Hepatic – A medicinal preparation, usually of herbal origin, used to “tone” and strengthen the liver, increase the flow of bile, and aid in hepatic detoxification (as defined by alternative health practitioners, rather than mainstream physicians).

Hypotensive – causing low blood pressure or a lowering of blood pressure.


Immune Stimulant – (Immune) the body’s system of defenses against infective organisms or other foreign bodies invading the body. (Stimulant) Serving as or being a stimulus; stimulating.

Insecticidal – a substance or agent used to kill insects and other arthropods.


Laxative – having a tendency to loosen or relax; specifically :  producing bowel movements and relieving constipation.

Lymphatic – of or relating to lymph or its secretion.


Mucolytic – capable of dissolving, digesting, or liquefying mucus.


Nerve Tonic – a medicine that acts therapeutically upon the nerves, particularly in the sense of a sedative that serves to calm ruffled nerves.

Nervine – a natural substance, such as an herb, which is calming to the nervous system.

Neuroprotective – serving to protect nerve cells from injury or degeneration.

Neurotonic – an agent that improves the tone or force of the nervous system.


Parasiticide – an agent that destroys parasites.

Prophylactic – an agent that tends to ward off disease.

Purifier – a device or substance that frees something of extraneous, contaminating, or debasing matter.


Radioprotective – giving protection against the effects of radiation.

Refreshing – able to or tending to refresh; invigorating.

Regenerative – tending to or characterized by regeneration.

Repellent (insect) – something that repels, as a substance that keeps away insects.

Revitalizer – to give new vitality or vigor to.

Rubefacient – an herb or substance used to bring blood rapidly to a concentrated area of the skin, thus causing redness of skin.


Sedative – allaying irritability, excitement, or nervousness.

Stimulant – an agent (as a drug) that produces a temporary increase of the functional activity or efficiency of an organism or any of its parts.

Stomachic – beneficial to or stimulating digestion in the stomach.

Styptic – tending to check bleeding by contracting the tissues or blood vessels; hemostatic.

Sudorific – causing or increasing sweat.


Tonic – a medicine that invigorates or strengthens.

Tonifying/Tonifier – impart tone to (the body or a part of it).


Vasoconstricting – (vasoconstrictor) an agent that causes narrowing of the blood vessels.

Vasodilator – a drug, agent, or nerve that can cause dilatation (vasodilatation) of the walls of blood vessels.

Vermifuge – destructive to parasitic worms; called also antihelmintic and vermifugal.

Vulnerary – of or relating to a wound or the healing of a wound.


Warming – causing or allowing you to feel warm.