Definition of roentgen in US English:

roentgen

(also R)

noun

  • A unit of ionizing radiation, the amount producing one electrostatic unit of positive or negative ionic charge in one cubic centimeter of air under standard conditions.

    • ‘A lethal exposure of radiation ranges from 300 to 500 roentgens an hour; levels in the tour areas vary from 15 to several hundred microroentgens an hour.’
    • ‘Some paramecium can withstand 200,000 roentgens.’
    • ‘This is also equivalent to exposure to a level of one roentgen.’
    • ‘She talked about rems and rads and roentgens per hour, and at first, he tried to memorize her words, but he wasn't able to commit the information to memory.’

Origin

1920s: named after Wilhelm Conrad Röntgen (1845–1923), German physicist, discoverer of X-rays.

Pronunciation