A pharmacon or pharmakon (from Greek: (φάρμακον), adapted from pharmacos) is a biologically active substance. It is used more broadly than the term drug because it includes endogenous substances, and biologically active substances which are not used as drugs. Typically the word pharmacon includes, pharmacological agonists and antagonists, ...
• (n.) A medicine or drug; also, a poison.
(Gr. pharmakon) a drug.
<pharmacology> A drug. ... Origin: Gr. Pharmakon ... (18 Nov 1997) ... 
Phar'ma·con noun [ New Latin , from Greek 
pharmacon A drug or a medicinal preparation.