Adjective

1. Pertaining to a master; magisterial; authoritative; dogmatic.
2. Commanded or prescribed by a magister, especially by a doctor; hence, effectual; sovereign; as, a magistral sirup.
3. Formulated extemporaneously, or for a special case; opposed to officinal, and said of prescriptions and medicines.

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.

Etymology