Other forms: prescribed, prescribing, prescribes
To prescribe is to order a medicine or a course of treatment. The doctor decides, and writes it down.
The written order is the prescription, and in Britain it is taken to a pharmacy and exchanged for the drug. The word also has a formal sense meaning to lay down as a rule, so regulations prescribe how something must be done. The trap is proscribe, which looks almost identical and means to forbid, so the two words are close to opposites. Prescriptive grammar is the kind that tells you what you ought to say.
To prescribe is to write beforehand. Latin prae, before, plus scrībō, to write: the doctor writes the order ahead of the treatment, and a rule is written ahead of the conduct it governs.
Proto-Indo-European
*(s)kreybʰ-
Latin
praescrībō
English, today
prescribe
Built from
Borrowed from Latin praescrībō. Latin praescrībere, from prae- (“before, in front”) and scribo (“to write”).
Etymology from Wiktionary, CC BY-SA