allude vs concern

allude is not a noun while concern is a noun.

Word	Noun	Adjective	Verb	Adverb
allude	No	No	Yes	No
concern	Yes	No	Yes	No

allude (noun)	concern (noun)
	something that interests you because it is important or affects you
	something or someone that causes anxiety; a source of unhappiness
	a feeling of sympathy for someone or something
	an anxious feeling
	a commercial or industrial enterprise and the people who constitute it

allude (verb)	concern (verb)
make a more or less disguised reference to	be relevant to
	be on the mind of