How to say "prescribe" in Japanese

• 定めるさだめるJLPT N1approx.Common
  ichidan verb, transitive verbCovers 'prescribe' in the sense of fixing rules, conditions, or procedures by authority, as a law, regulation, or contract does; being the common word, it is the usual choice for this meaning.
  職員しょくいんの選考せんこうに関かんする規則きそくを次つぎのように定さだめる。↗

  Rules in connection with staff selection are set as follows.
• 定むさだむ
  nidan verb (archaic)Shares the senses of establishing, laying down, and prescribing rules, but is less common; for saying that a law or rule prescribes something, 定める is almost always the word you want.

Both verbs cover 'prescribe' only in its sense of laying down rules, conditions, or procedures, as a law does: use the common 「定める」; the less common 「定む」 is seldom needed, and neither is used for prescribing medication.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 定めるさだめるto establish
• 盛るもるto administer (medicine, poison)
• 定むさだむto establish