x-ray

or X-ray (ĕks′rā′)

n. or x ray or X ray

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.

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.]

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ThesaurusAntonymsRelated WordsSynonymsLegend:

Noun	1.	X ray - electromagnetic radiation of short wavelength produced when high-speed electrons strike a solid target roentgen ray, X-radiation, X-ray ionizing radiation - high-energy radiation capable of producing ionization in substances through which it passes electromagnetic radiation, electromagnetic wave, nonparticulate radiation - radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge
	2.	X ray - a radiogram made by exposing photographic film to X rays; used in medical diagnosis roentgenogram, X-ray photograph, X-ray picture, X-ray angiocardiogram - a series of X rays representing the action of the heart and its blood vessels after the injection of a radiopaque substance angiogram - an X-ray representation of blood vessels made after the injection of a radiopaque substance; "angiograms are produced by angiography" arteriogram - an X ray of an artery filled with a contrast medium arthrogram - an X ray of a joint after the injection of a contrast medium pneumoencephalogram, encephalogram - an X ray of the brain made by replacing spinal fluid with a gas (usually oxygen) to improve contrast hysterosalpingogram - X ray of the uterus and Fallopian tubes; usually done in diagnosing infertility (to see if there any blockages) mammogram - X-ray film of the soft tissue of the breast myelogram - X-ray film of the spinal cord and spinal nerve roots and subarachnoid space pyelogram - an X ray of the kidneys and ureters radiograph, shadowgraph, skiagram, skiagraph, radiogram - a photographic image produced on a radiosensitive surface by radiation other than visible light (especially by X-rays or gamma rays) phlebogram, venogram - an X ray of a vein injected with a radiopaque contrast medium