(pharmacology) A sovereign medicine or remedy.
(countable) A magistral line.
(chiefly uncountable) Powdered copper pyrites used in the amalgamation of ores of silver, as at the Spanish mines of Mexico and South America.
Pertaining to or befitting a master; authoritative.
(pharmacology) Formulated extemporaneously, or for a special case; opposed to officinal, and said of prescriptions and medicines.