emission vs radiation

emission and radiation both are nouns.

Word	Noun	Adjective	Verb	Adverb
emission	Yes	No	No	No
radiation	Yes	No	No	No

As nouns, radiation is a hyponym of emission; that is, radiation is a word with a more specific, narrower meaning than emission:

Other hyponyms of emission include discharge, venting.

As nouns, radiation is a hyponym of emission; that is, radiation is a word with a more specific, narrower meaning than emission:

emission: the release of electrons from parent atoms
radiation: the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay

emission (noun)	radiation (noun)
the act of emitting; causing to flow forth	the act of spreading outward from a central source
the occurrence of a flow of water (as from a pipe)	(medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
the release of electrons from parent atoms	a radial arrangement of nerve fibers connecting different parts of the brain
any of several bodily processes by which substances go out of the body	the spread of a group of organisms into new habitats
a substance that is emitted or released	energy that is radiated or transmitted in the form of rays or waves or particles
	the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
	syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions); low doses cause diarrhea and nausea and vomiting and sometimes loss of hair; greater exposure can cause sterility and cataracts and some forms of cancer and other diseases; severe exposure can cause death within hours