Above the ordinary in amount, extent, worth, or value; especially good or great; special… Of remedies, medicines, etc.: Excellent; highly…

Of remedies, etc.: Efficacious or potent in a superlative degree. Frequently in figurative use.

Pharmacology. Of a remedy: sovereign, supremely effective. Obsolete.

= magistral, adj. 2.

Of a plant, liquid, or other substance: having (magical) healing properties; affecting the body in a beneficial manner; potent; strengthening…

Of a medicine, treatment, etc.: efficacious, potent. Also with against. Obsolete.

That is or proves to be superior in any contest; victorious; ruling; effective, influential.