Definitions of R
  1. noun
    the 18th letter of the Roman alphabet
    synonyms: r
    see moresee less
    type of:
    alphabetic character, letter, letter of the alphabet
    the conventional characters of the alphabet used to represent speech
  2. noun
    (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 constant, universal gas constant
    see moresee less
    type of:
    a number representing a quantity assumed to have a fixed value in a specified mathematical context
  3. noun
    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
    see moresee less
    type of:
    radioactivity unit
    a measure of radioactivity
Word Family
F1 image

Express yourself in 25 languages

  • Learn immersively - no memorization required
  • Build skills for real-world conversations
  • Get immediate feedback on your pronunciation
Get started for $7.99/month