magistral

(noun, adjective)

adjective

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.]

noun

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.