noun An electromagnetic wave of high energy and very short wavelength, which is able to pass through many materials opaque to light. (Gamma rays are not particles but a form of electromagnetic radiation, like light, radio waves, and X-rays.) A photographic or digital image of the internal composition of something, especially a part of the body, produced by X-rays being passed through it and being absorbed to different degrees by different materials. (the fracture was clearly visible on the X-ray) A code word representing the letter X, used in radio communication.
verb Photograph or examine with X-rays. (luggage bound for the hold is X-rayed)