Acrid - Having a hot, biting taste or causing heat and irritation when applied to the skin.

Adjuvant - A herb added to a mixture to aid the effect of the principle ingredient.

Alterative - An agent which produces gradual beneficial change in the body, usually by improving nutrition, without having any marked specific effect and without causing sensible evacuation.

Analgesic - A drug which relieves or diminishes pain; anodyne.

Anaphrodisiac - An agent which reduces sexual desire or potency.

Anaesthetic - An agent that deadens sensation.

Anodyne - An agent that soothes or relieves pain.

Anthelmintic - An agent that destroys or expels intestinal worms; vermicide; vermifuge.

Antibiotic - An agent that destroys or arrests the growth of micro-organisms.

Anticoagulant - An agent that prevents clotting in a liquid, as in blood.

Antiemetic - An agent that counteracts nausea and relieves vomiting.

Antihydrotic - An agent which reduces or suppresses perspiration.

Antilithic - An agent which reduces or suppresses urinary calculi (stones) and acts to dissolve those already present.

Antiperiodic - An agent which counteracts periodic or intermittent diseases, (such as malaria).

Antiphlogistic - An agent which reduces inflammation.

Antipyretic - An agent which prevents or reduces fever. ( see also frebrifuge).

Antiscorbutic - An source of vitamin C for curing or preventing scurvy.

Antiscrofulous - Counteracting scrofula.

Antiseptic - An agent for destroying or inhibiting pathogenic or putrefactive bacteria.

Antispasmodic - An agent that relieves or checks spasms or cramps.

Antitussive - An agent that relieves coughing.

Aperient - A mild stimulant for the bowels; a gentle purgative.

Aphrodisiac - An agent for arousing or increasing sexual desire or potency.

Appetiser - An agent that excites the appetite.

Aromatic - A substance having an agreeable odour and stimulating qualities.