[ rent-guhn, -juhn, ruhnt-; for 1 also German rœnt-guhn ]

  1. Wil·helm Kon·rad [wil-helm kon-rad; German vil-helm kawn-raht], /ˈwɪl hɛlm ˈkɒn ræd; German ˈvɪl hɛlm ˈkɔn rɑt/, 1845–1923, German physicist: discoverer of x-rays 1895; Nobel Prize 1901.

  2. (lowercase)Physics. a unit of exposure dose that measures x-rays or gamma rays in terms of the ions or electrons produced in dry air at 0° C and one atmosphere, equal to the amount of radiation producing one electrostatic unit of positive or negative charge per cubic centimeter of air. Abbreviation: r, R

  1. (sometimes lowercase) of or relating to Wilhelm Roentgen, the Roentgen unit, or especially to x-rays.

Words Nearby Roentgen Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use Roentgen in a sentence

  • But nothing less than the Roentgen ray would have revealed the young man, who was stealthily watching the ferocious buck.

    Two Boys in Wyoming | Edward S. Ellis
  • Nothing could more vividly bear out this gentleman than contemplation of the possibilities of the Roentgen ray.

    Peeps at People | Robert Cortes Holliday
  • He discovered that sound-vibrations rule the universe, that they may be turned into a musical Roentgen ray.

    Melomaniacs | James Huneker
  • I must tell you of my own experiences in connection with these X-rays, which I hear some men describe also as Roentgen rays.

    Autobiography of an Electron | Charles R. (Charles Robert) Gibson
  • When the flying electrons strike upon a little metal target placed in their path, they produce the well-known Roentgen rays.

    Autobiography of an Electron | Charles R. (Charles Robert) Gibson

British Dictionary definitions for roentgen (1 of 2)



/ (ˈrɒntɡən, -tjən, ˈrɛnt-) /

  1. a unit of dose of electromagnetic radiation equal to the dose that will produce in air a charge of 0.258 × 10 –3 coulomb on all ions of one sign, when all the electrons of both signs liberated in a volume of air of mass one kilogram are stopped completely: Symbol: R, r

Origin of roentgen

C20: named after W. K. Roentgen

British Dictionary definitions for Roentgen (2 of 2)



/ (ˈrɒntɡən, -tjən, ˈrɛnt-, German ˈrœntɡən) /

  1. Wilhelm Konrad (ˈvɪlhɛlm ˈkɔnraːt). 1845–1923, German physicist, who in 1895 discovered X-rays: Nobel prize for physics 1901

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for Roentgen


[ rĕntgən, rĕntjən ]

  1. German physicist who discovered x-rays in 1895 and went on to develop x-ray photography, which revolutionized medical diagnosis. In 1901 he was awarded the Nobel Prize for physics.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.