(1):
(a.) Commanded or prescribed by a magister, esp. by a doctor; hence, effectual; sovereign; as, a magistral sirup.
(2):
(a.) Pertaining to a master; magisterial; authoritative; dogmatic.
(3):
(a.) Formulated extemporaneously, or for a special case; - opposed to officinal, and said of prescriptions and medicines.
(4):
(n.) A sovereign medicine or remedy.
(5):
(n.) A magistral line.
(6):
(n.) Powdered copper pyrites used in the amalgamation of ores of silver, as at the Spanish mines of Mexico and South America.