correspondent vs similar

correspondent is a noun but similar is not a noun.

Word	Noun	Adjective	Verb	Adverb
correspondent	Yes	Yes	No	No
similar	No	Yes	No	No

correspondent (noun)	similar (noun)
someone who communicates by means of letters
a journalist employed to provide news stories for newspapers or broadcast media

correspondent (adjective)	similar (adjective)
similar or equivalent in some respects though otherwise dissimilar	marked by correspondence or resemblance
	resembling or similar; having the same or some of the same characteristics; often used in combination
	having the same or similar characteristics
	capable of replacing or changing places with something else; permitting mutual substitution without loss of function or suitability
	(of words) expressing closely related meanings