Definition of Rx
: prescription 4a, c
Did You Know?
The "R" in "Rx" stands for the Latin word recipe, meaning "take," and the first doctor to use "Rx" used it as a verb with the same meaning, "Rx two aspirin" being equivalent to today's "Take two aspirin." (The word recipe had had the same function from the 13th through the 17th centuries.) Those two letters were a 19th-century take on a 16th-century symbol, the letter R with a line through its slanted leg-the line signaling that the "R" is functioning as an abbreviation. It wasn't till the early 20th century that "Rx" came to be used as the noun we know today. As for the noun "recipe," it followed the same trajectory, referring to a medical prescription for about 100 years before it developed its connection with cooking in the early 17th century.
Origin and Etymology of rx
alteration of ℞, symbol used at the beginning of a prescription, abbreviation for Latin recipe, literally, take — more at recipe
First Known Use: 1926
RX Defined for English Language Learners
Definition of Rx for English Language Learners
: a doctor's prescription
Medical Definition of Rx
: a medical prescription
Seen and Heard
What made you want to look up Rx? Please tell us where you read or heard it (including the quote, if possible).