Planckian radiator
blackbody
ideal thermal radiator that absorbs completely all incident radiation, whatever the wavelength, the direction of incidence or the polarization
Note 1 to entry: A Planckian radiator has, for any wavelength and any direction, the maximum spectral distribution of radiance for a thermal radiator in thermal equilibrium at a given temperature.
Note 2 to entry: This entry was numbered 845-04-04 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-960 and 17-93 in CIE S 017:2011.