prescription
noun
1.
directions prescribed beforehand; the action of prescribing authoritative rules or directions
Derived from:
prescribe 2.
a drug that is available only with written instructions from a doctor or dentist to a pharmacist
3.
written instructions for an optician on the lenses for a given person
4.
written instructions from a physician or dentist to a druggist concerning the form and dosage of a drug to be issued to a given patient