Definition of prescribe verb from the Oxford Advanced Learner's Dictionary. (of a doctor) to tell somebody to take a particular medicine or have a particular treatment; to write a prescription for a particular medicine, etc. prescribe something Valium is usually prescribed to treat anxiety. The meaning of PRESCRIBE is to lay down a rule : dictate. How to use prescribe in a sentence. 1. To set down as a rule, law, or direction: prescribed the terms of the surrender. 2. To order the use of (a medicine or other treatment). The product will have to meet internationally prescribed (= demanded) standards. 2 meanings: 1. recommended by a doctor 2. laid down or recommended formally. Click for more definitions. established or decided beyond dispute or doubt adjective conforming to set usage, procedure, or discipline “in prescribed order” synonyms: official regular in accordance with fixed order or procedure or principle PRESCRIBED definition: dictated or indicated as a rule or course of action to be followed. See examples of prescribed used in a sentence.