roentgen

UK: /ˈrɒntɡən/

US: /ˈrɛntgən, -dʒən, ˈrʌnt-/

US: (rent′gən, -jən, runt′-; for 1 also Ger. rœnt′gən)

WordReference Random House Learner's Dictionary of American English © 2025

roent•gen /ˈrɛntgən, -dʒən, ˈrʌnt-/   n. [countable]

1. Physics a unit of radiation dosage.

Collins Concise English Dictionary © HarperCollins Publishers::

roentgen, röntgen / ˈrɒntɡən -tjən ˈrɛnt-/ noun

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

Etymology: 20th Century: named after W. K. Roentgen

WordReference Random House Unabridged Dictionary of American English © 2025

Roent•gen  (rent′gən, -jən, runt′-; for 1 also Ger. rœnt′gən), n. 

Wil•helm Kon•rad  (wil′helm kon′rad; Ger. vil′helm kôn′rät), 1845–1923, German physicist: discoverer of x-rays 1895;
Nobel prize 1901.
1. Physics (l.c.) 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. Abbr.: r, R

adj. 

2. Physics (sometimes l.c.) of or pertaining to Wilhelm Roentgen, the Roentgen unit, or esp. to x-rays.

Also, Röntgen. 

Collins Concise English Dictionary © HarperCollins Publishers::

Roentgen, Röntgen / ˈrɒntɡən -tjən ˈrɛnt-/ / ˈrœntɡən/ noun

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