1 a obsolete : a substance used in dyeing or chemical operations b : a substance used as a medication or in the preparation of medication c according to the ...
a. A substance used in the diagnosis, treatment, or prevention of a disease or as
a component of a medication. b. Such a substance as recognized or
Therapeutic agent; any substance, other than food, used in the prevention, diagnosis, alleviation, treatment, or cure of disease. For types or classifications of ...
1A medicine or other substance which has a physiological effect when ingested
or otherwise introduced into the body: a new