x-ray or X-ray (ĕksrā′)
n. or x ray or X ray
1.
a. A photon of electromagnetic radiation of very short wavelength, ranging from about 10 down to 0.01 nanometers, and very high energy, ranging from about 100 up to 100,000 electron volts.
b. often x-rays or X-rays A narrow beam of such photons. X-rays are used for their penetrating power in radiography, radiology, radiotherapy, and scientific research. Also called roentgen ray.
2.
a. A photograph taken with x-rays.
b. The act or process of taking such a photograph: Did the patient move during the x-ray?
tr.v. x-rayed, x-ray·ing, x-rays or X-rayed or X-ray·ing or X-rays
1. To irradiate with x-rays.
2. To photograph with x-rays.
[From translation of obsolete German X-Strahlen, x-rays (coined by their discoverer Wilhelm Conrad Roentgen ) : x, x, unknown factor (since x-rays were a previously unknown form of radiation) + Strahlen, pl. of Strahle, ray.]
x-rayof an adult human hand