n. A magisterial injunction; an authoritative mandate.n. In alchemy, a magisterium or magistral; in chem., one of various extracts or preparations, especially magisterium bismuthi, a precipitate formed when water is added to a solution of bismuth in nitric acid. See the quotations from Boyle and Boerhaave.n. Any kind of medicine or remedial agency asserted to be of exceptional efficacy.