n.
    - an instruction written by a medical practitioner that authorizes a patient to be issued with a medicine or treatment.
 - the action of prescribing.
 - an authoritative recommendation or ruling.
 - 
(also positive prescription)
 Law  the establishment of a claim founded on the basis of long usage or custom.
 
 
  Etymology
  ME: via OFr. from L. praescriptio(n-), from praescribere (see prescribe).