x-ray

American  

[eks-rey] / ˈɛksˌreɪ /

Or X-ray

noun

1. Physics.

   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 nanometers.

2. a radiograph made by x-rays.

3. (initial capital letter) a word in communications to represent the letter X.

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verb (used with object)

1. to examine, photograph, or treat with x-rays.

adjective

1. of or relating to x-rays.

   x-ray examination of the digestive tract.

2. able to see through objects that are opaque.

   the x-ray vision of Superman and other superheroes.

3. able to clearly and keenly perceive or recognize something that is not outwardly visible.

   a teacher with x-ray intuition about her students.

X-ray British  

noun

1. 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

2. 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

3. (usually capital) communications a code word for the letter x

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verb

1. to photograph (part of the body, etc) using X-rays

2. to treat or examine by means of X-rays

x-ray Scientific  

/ ĕks′rā′ /

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 10 ¹⁶ to 10 ¹⁹ 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.

2. See more at electromagnetic spectrum

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

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x-ray ¹ Cultural  

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

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x-ray ² Cultural  

1. 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.

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Discover More

Because x-rays can travel through solid material and affect photographic plates, they are widely used in diagnosing medical problems.

Objects in the sky also send out x-rays in processes that use very high energy.

Etymology

Origin of x-ray

First recorded in 1895–1900; translation of German X-Strahl (1895), the name originally given to the rays by Röntgen, their discoverer, x signifying their unknown nature

Example Sentences

To investigate these strange behaviors, scientists used extremely fast x-ray pulses generated by powerful lasers in South Korea.

From Science Daily • Mar. 29, 2026

"I don't see an ICE agent looking at an x-ray machine, because you're not trained in that," he said on CNN's "State of the Union."

From Barron's • Mar. 22, 2026

A technical take is more like an x-ray that might pinpoint unhealthy symptoms a bit sooner.

From The Wall Street Journal • Mar. 11, 2026

ARG began the process of identifying which tiles needed the most remediation by doing a photorealistic laser scan of the building that MacLean described as a sort of high-tech x-ray.

From Los Angeles Times • Nov. 10, 2025

“We won’t know until we x-ray it. It may be worse if you don’t stop moving that leg.”

From "Friday Night Lights: A Town, A Team, And A Dream" by H.G. Bissinger

Related Words

• Roentgen rays
• Röntgen rays
• radioactivity