magistral

Of, relating to, or befitting a master; authoritative.

Formulated extemporaneously, or for a special case; opposed to officinal, and said of prescriptions and medicines.

(no longer used) Sovereign (of a remedy); extremely effective.

A sovereign medicine or remedy.

A magistral line.

Powdered copper pyrites used in the amalgamation of ores of silver, as at the Spanish mines of Mexico and South America.