Mag·is·tral a.
1. Pertaining to a master; magisterial; authoritative; dogmatic.
2. Commanded or prescribed by a magister, esp. by a doctor; hence, effectual; sovereign; as, a magistral sirup. “Some magistral opiate.”
3. Pharmacy Formulated extemporaneously, or for a special case; -- opposed to officinal, and said of prescriptions and medicines.
Magistral line Fort., the guiding line, or outline, by which the form of the work is determined. It is usually the crest line of the parapet in fieldworks, or the top line of the escarp in permanent fortifications.