Pronunciation: (rent'gun, -jun, runt'-; for 1 also Ger. rœnt'gun),[key] —n. 1. Wil•helm Kon•rad Pronunciation: (wil'helm kon'rad; Ger. vil'helm kôn'rät),[key] 1845–1923, German physicist: discoverer of x-rays 1895; Nobel prize 1901.
2. (l.c.) 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. Abbr.: r, R
—adj. (sometimes l.c.) of or pertaining to Wilhelm Roentgen, the Roentgen unit, or esp. to x-rays. Also,Röntgen.