A hypothetical body whose surface absorbs no electromagnetic radiation of any wavelength, i.e., one which exhibits zero absorptivity for all wavelengths; an idealization exactly opposite to that of the black body.
In nature, no true white bodies are known. Most white pigments possessing high reflectivity for visible radiation are fairly good absorbers in the infrared; hence, they are not white bodies in the sense of the radiation theory. However, the term white body is used for physical objects with respect to a particular wavelength interval.
See also: Blackbody.