nuclear vs nucleus

nuclear is not a noun while nucleus is a noun.

Word	Noun	Adjective	Verb	Adverb
nuclear	No	Yes	No	No
nucleus	Yes	No	No	No

nuclear (noun)	nucleus (noun)
	a part of the cell containing DNA and RNA and responsible for growth and reproduction
	any histologically identifiable mass of neural cell bodies in the brain or spinal cord
	the central structure of the lens that is surrounded by the cortex
	a small group of indispensable persons or things
	the positively charged dense center of an atom
	(astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail

nuclear (adjective)	nucleus (adjective)
(weapons) deriving destructive energy from the release of atomic energy
of or relating to or constituting the nucleus of an atom
of or relating to or constituting the nucleus of a cell
constituting or like a nucleus