Meaning

noun directions prescribed beforehand; the action of prescribing authoritative rules or directions

noun a drug that is available only with written instructions from a doctor or dentist to a pharmacist

noun written instructions for an optician on the lenses for a given person

originBorrowed from Middle French, from Old French prescripcion, from Latin praescriptio (“preface; pretext; something written ahead of time”), from prae- (“pre-, before”) + scribere (“to write”) + -tio (“-tion, forming nouns”). Equivalent to prescribe + -tion.

Etymology from Wiktionary, CC BY-SA 3.0