1. Pertaining to or befitting a master; authoritative. [from 16th c.]
2. (obsolete, pharmacology) Sovereign (of a remedy); extremely effective. [16th-17th c.]
3. (pharmacology) Formulated extemporaneously, or for a special case; opposed to officinal, and said of prescriptions and medicines. [from 16th c.]
1. A sovereign medicine or remedy.
2. A magistral line.
3. Powdered copper pyrites used in the amalgamation of ores of silver, as at the Spanish mines of Mexico and South America.