R — English Dictionary

Character

1. The eighteenth letter of the English alphabet, called ar and written in the Latin script.

   Usage

   • letter
   • uppercase

Numeral

1. The eighteenth numeral symbol of the English alphabet, called ar and written in the Latin script.

   Usage

   • uppercase
   • number

Noun

1. Abbreviation of Rex (“King”) or Regina (“Queen”), the initial by which a British monarch signs documents after his or her name. The Crown, the government of a monarchy.

   Examples

   The English case of R v R [1992] AC 599 ruled that rape can be committed by a husband against his wife.

Proper noun

1. A programming language for statistics and data visualization.

Noun

1. a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air

   Synonyms

   roentgen

   Broader terms

   radioactivity unit

2. (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole

   Synonyms

   gas constantuniversal gas constant

   Broader terms

   constant

3. the 18th letter of the Roman alphabet

   Synonyms

   r

   Broader terms

   letterletter of the alphabetalphabetic character