Try Our Apps


Avoid these words. Seriously.


or X-ray

[eks-rey] /ˈɛksˌreɪ/
noun, Also, x ray, X ray
  1. Often, x-rays. a form of electromagnetic radiation, similar to light but of shorter wavelength and capable of penetrating solids and of ionizing gases.
  2. such radiation having wavelengths in the range of approximately 0.1–10 nm.
a radiograph made by x-rays.
(initial capital letter) a word in communications to represent the letter X.
verb (used with object)
to examine, photograph, or treat with x-rays.
of or relating to x-rays.
Origin of x-ray
1895-1900; translation of German X-Strahl (1895), the name orig. given to the rays by Röntgen, their discoverer, x signifying their unknown nature Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
British Dictionary definitions for xray


  1. electromagnetic radiation emitted when matter is bombarded with fast electrons. X-rays have wavelengths shorter than that of ultraviolet radiation, that is less than about 1 × 10–8 metres. They extend to indefinitely short wavelengths, but below about 1 × 10–11 metres they are often called gamma radiation
  2. (as modifier): X-ray astronomy
a picture produced by exposing photographic film to X-rays: used in medicine as a diagnostic aid as parts of the body, such as bones, absorb X-rays and so appear as opaque areas on the picture
(usually capital) (communications) a code word for the letter x
verb (transitive)
to photograph (part of the body, etc) using X-rays
to treat or examine by means of X-rays
Word Origin
C19: partial translation of German X-Strahlen (from Strahl ray), coined by W. K. Roentgen in 1895
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for xray



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.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
xray in Medicine

x-ray or X-ray
n. or x ray or X ray

  1. A relatively high-energy photon with wavelength in the approximate range from 0.01 to 10 nanometers. Also called roentgen ray.

  2. 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.

  3. A photograph taken with x-rays.

v. x-rayed or X-rayed, x-ray·ing or X-ray·ing, x-rays or X-rays
  1. To irradiate with x-rays.

  2. To photograph with x-rays.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
xray in Science
x-ray also X-ray
  1. A high-energy stream of electromagnetic radiation having a frequency higher than that of ultraviolet light but less than that of a gamma ray (in the range of approximately 1016 to 1019 hertz). X-rays are absorbed by many forms of matter, including body tissues, and are used in medicine and industry to produce images of internal structures. See more at electromagnetic spectrum.

  2. An image of an internal structure, such as a body part, taken with x-rays.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
xray in Culture

x-ray definition

A form of electromagnetic radiation with very high frequency and energy. X-rays lie between ultraviolet radiation and gamma radiation on the electromagnetic spectrum.

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.

x-ray definition

A photograph or image obtained through the use of x-rays. An x-ray is taken when an image of internal body structures (such as bones or organs) is needed to diagnose disease or determine the extent of injuries.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Nearby words for xray

Difficulty index for x-ray

Some English speakers likely know this word

Word Value for xray

Scrabble Words With Friends