x ray Definition

—used as a code word for the letter x

to examine, treat, or photograph with X-rays

any of the electromagnetic radiations that have an extremely short wavelength of less than 100 angstroms and have the properties of penetrating various thicknesses of all solids, of producing secondary radiations by impinging on material bodies, and of acting on photographic films and plates as light does

a photograph obtained by use of X-rays

astronomy dealing with investigations of celestial bodies by means of the X-rays they emit

a scattering of X-rays by the atoms of a crystal that produces an interference effect so that the diffraction pattern gives information on the structure of the crystal or the identity of a crystalline substance

a luminous celestial object emitting a major portion of its radiation in the form of X-rays —called also X-ray source

medical treatment (as of cancer) by controlled application of X-rays

a vacuum tube in which a concentrated stream of electrons strikes a metal target and produces X-rays

absorptiometry in which the density or mass of a material (such as bone) is measured by comparing the material's absorption of X-rays of two different energies and which is used especially for determining the mineral content of bone —abbreviation DEXA, DXA