Real Dictionary

X-ray in American English
a band of electromagnetic radiation with wavelengths between gamma rays and ultraviolet radiation ( c. .005 to c. 5 nanometers), produced by the bombardment of a substance (usually one of the heavy metals) by a stream of electrons moving at great velocity
of, by, or having to do with X-rays
to examine, treat, or photograph with X-rays
noun: a form of electromagnetic radiation, similar to light but of shorter wavelength and capable of penetrating solids and of ionizing gases

X-ray in British English
to photograph (part of the body, etc) using X-rays
noun: 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 ×