℞

• Rx, r.

An R with a cross-stroke indicating an abbreviation (of recipe, response, retrograde etc). In the case of a prescription, abbreviating Latin recipe (“take this”, second-person singular imperative of recipiō); it is sometimes typeset as, or even interpreted as, a digraph Rx. Compare also Dx (“diagnose, diagnosis”) and Hx (“history”).

℞

1. (medicine, pharmacy, Canada, US, Philippines) Prescription.
2. (medicine, pharmacy) Take (used to begin a list of ingredients of a compound).
   • 1583, Philip Barrough [i.e., Philip Barrow], “Of Making Bolus”, in The Methode of Phisicke, Conteyning the Causes, Signes, and Cures of Inward Diseases in Mans Body from the Head to the Foote. […], London: […] Thomas Vautroullier […], →OCLC, book VI, page 288:

     BOlvs in Engliſh is called a morſell. It is a medicine laxatiue, in forme & faſhion it is meanely whole, & it is ſwallowed by litle gobbets. […] ℞. medulla caſiæ fiſtulæ newly drawen. ℥. j. or ʒ. x. the graines (that is the kernelles) of barbaries. ℈. ß. and with ſugar roſet [sugar compounded with rose petals] make a bole.

3. (liturgy) Marks the congregation's response to the versicle.

   Synonym: R

4. (astrology) Retrograde.

The Medieval Unicode Font Initiative recommends that medieval scholars use U+211E for all meanings, medicinal and liturgical.

℞

1. (chiefly Medieval Latin) abbreviation of rex, king.
2. (chiefly New Latin, pharmacy) abbreviation of recipe, take (as an imperative).