I. ˈrent-gən, ˈrənt-, -jən, -shən adjective
Etymology: International Scientific Vocabulary, from Wilhelm Röntgen
Date: 1896
: of or relating to X-rays
roentgen examinations
II. noun
Date: 1922
: the international unit of x-radiation or gamma radiation equal to the amount of radiation that produces in one cubic centimeter of dry air at 0°C and standard atmospheric pressure ionization of either sign equal to one electrostatic unit of charge