Origin: Latin suffix -tion
Prescription has 7 different meanings across 2 categories:
directions prescribed beforehand; the action of prescribing authoritative rules or directions
"I tried to follow her prescription for success"
a drug that is available only with written instructions from a doctor or dentist to a pharmacist
"he told the doctor that he had been taking his prescription regularly"
written instructions for an optician on the lenses for a given person
"After getting my eyes checked, the doctor gave me a new prescription that listed the exact lens power needed to correct my vision."
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
"After my checkup, the doctor gave me a new prescription for antibiotics that I need to pick up at the pharmacy."
The act of prescribing a rule, law, etc..
"The new manager's prescription for office hours has caused quite an uproar among the staff."
In plain English: A prescription is a doctor's written order telling a pharmacy which medicine to give you and how much to take.
"The doctor gave me a prescription for some painkillers to help with my backache."
Usage: In everyday usage, a prescription is a written order from a doctor authorizing a patient to receive specific medication or medical treatment. Do not use this word to refer to the general act of setting rules or laws, which is a rare formal definition rather than common speech.
only available with a physician or nurse practitioner's written prescription
"You can't buy that medication over the counter because it requires a doctor's prescription."
In plain English: A prescription adjective describes something that is required by a doctor's order to be filled at a pharmacy.
"The doctor gave me a prescription bottle for my new medication."
Usage: Use "prescription" as an adjective only when describing items that can legally be obtained solely through a doctor's written order. For example, say "prescription drugs" to distinguish them from over-the-counter medicines available without such authorization.
The word prescription comes from the Middle French prescripcion and ultimately Latin praescriptio, which originally meant a preface or something written ahead of time. It entered English as a noun form related to the verb prescribe, combining the idea of writing instructions before an event occurs.