TKG English Learner's Dictionary

x-ray

x-raynoun

American /ˈɛks.reɪ/ British /ˈeks.reɪ/
Also spelled: X-ray (also written with a capital X)
plural x-rays
common

An x-ray is a kind of energy that passes through solid things, the picture made with it, and the medical test in which that picture is taken.

  1. the raysa form of energy that can pass through solid things, used to make pictures of the inside of the body or of an object

    countable [C] usually plural [usu pl] often before another noun [before noun] physics

    Collocations

    noun + noun x-ray machine, x-ray scanner, x-ray equipment
    noun + verb x-rays pass through something
    verb + noun use x-rays

    Compare radiation

  2. the picturea photograph of the bones or the inside of the body, or of the inside of an object, made with this form of energy

    countable [C]

    Collocations

    verb + noun take an x-ray, look at an x-ray, read an x-ray
    noun + noun a chest x-ray, a hand x-ray
    adjective + noun a dental x-ray
    noun + preposition an x-ray of
    noun + verb an x-ray shows something

    Compare scan (a scan is usually a picture made by another kind of machine, such as an MRI scanner)

  3. the examinationa medical test in which such a photograph is taken

    countable [C] often before another noun [before noun]

    Collocations

    verb + noun have an x-ray, go for an x-ray, need an x-ray, send someone for an x-ray
    noun + noun x-ray department, x-ray appointment
    adjective + noun a routine x-ray

Word family

Usage

The word is written x-ray or X-ray, always with a hyphen; the plural is x-rays. You take an x-ray (make the picture) or have an x-ray (go through the examination). The verb x-ray means take an x-ray of: they x-rayed her hand.

Common mistakes

The doctor made an x-ray of my hand. The doctor took an x-ray of my hand.
The verb for making the picture is take, as with a photograph.

Word origin

The x is the letter that stands for an unknown amount in a calculation: the scientist who discovered the rays did not know what they were, and named them X-Strahlen in German. English kept the x and translated Strahlen as ray.

Checked against: Wiktionary, Online Etymology Dictionary (2026-09-16)

For translators

Meaning across languages In many languages the rays and the examination are named after the physicist who discovered them, and the picture has a word of its own. English uses x-ray for all three senses: the rays, the picture, and the examination.
Grammar trap Countable in all senses: an x-ray, two x-rays; the rays themselves are usually plural. Take an x-ray means make the picture; have an x-ray means be examined. Before a noun: an x-ray machine, the x-ray department.
Cultural background Airports and some public buildings use x-ray machines to check bags, and dentists take x-rays of teeth as a routine part of a checkup. A scan is a different kind of picture, made by other machines.
Pronunciation trap Two clear syllables with the stress on the first: EKS-ray. The letter x is pronounced eks, and the second syllable rhymes with day.