1896, translation of German X-strahl, from X, algebraic symbol for an unknown quantity, + Strahl (plural Strahlen) "beam, ray." Coined 1895 by German scientist Wilhelm Conrad Röntgen (1845-1923), who discovered them.
x-ray or X-ray
n. or x ray or X ray
A relatively high-energy photon with wavelength in the approximate range from 0.01 to 10 nanometers. Also called roentgen ray.
A stream of such photons used for their penetrating power in radiography, radiology, radiotherapy, and scientific research. Often used in the plural. Also called roentgen ray.
A photograph taken with x-rays.
To irradiate with x-rays.
To photograph with x-rays.
|x-ray also X-ray|
Note: Because x-rays can travel through solid material and affect photographic plates, they are widely used in diagnosing medical problems.
Note: Objects in the sky also send out x-rays in processes that use very high energy.