How To Use Blackbody In A Sentence

The term perfect blackbody applies to bodies that act as perfect radiators or absorbers of heat.
Patrick 027 (210), a thought that might shed some light (and which has been debated in RC with vigorous opposition I should admit) is that the IR emitted radiation from the vibration energy of CO2 molecules is not the same mechanism that generates the so-called blackbody RealClimate
In 1893 Wien stated his displacement law of blackbody radiation spectra at different temperatures.
The amount of blackbody energy emitted is strictly and solely a function of the thermal temperature of the substance, mitigated by the characteristic of the substance called emissivity (which can, as you say, by frequency dependent). RealClimate
The core element of multifunction lining lies in the blackbody, with emission rate 0.96.

The blackbody spectrum at 293 K = 70 F peaks at 9.9 um and emits 32% of its total energy in the same waveband. Mann: "I Am Not A Statistician" « Climate Audit
This is opposed to a blackbody in the sense that the atmosphere might not be perfectly opaque, but the emitted radiation would still be called blackbody radiation and it would obey the rules of blackbody radiation. RealClimate
For E = h-bar omega I guess you can refer to planck blackbody, and make a leap that it will hold for matter waves as well (just like deBroglie did!) Everything You Ever Wanted to Know About Quantum Mechanics, But Were Afraid to Ask
It follows, then, that any radiation emitted by the cavity radiator corresponds to the definition of blackbody radiation.