Full radiator and Natural object

Full radiator noun - A hypothetical object capable of absorbing all the electromagnetic radiation falling on it.

Natural object and full radiator are semantically related. In some cases you can use "Natural object" instead a noun phrase "Full radiator".

Natural object noun - An object occurring naturally; not made by man.

Full radiator and natural object are semantically related. Sometimes you can replace phrase "Full radiator" with "Natural object", this phrases are similar.