appear vs gleam

appear is not a noun while gleam is a noun.

Word	Noun	Adjective	Verb	Adverb
appear	No	No	Yes	No
gleam	Yes	No	Yes	No

As verbs, gleam is a hyponym of appear; that is, gleam is a word with a more specific, narrower meaning than appear:

Other hyponyms of appear include fulminate, occur.

As verbs, gleam is a hyponym of appear; that is, gleam is a word with a more specific, narrower meaning than appear:

appear: give a certain impression of being something or having a certain aspect
gleam: be shiny, as if wet

appear (noun)	gleam (noun)
	an appearance of reflected light
	a flash of light (especially reflected light)

appear (verb)	gleam (verb)
come into sight or view	to shine with faint or brief light
be issued or published	shine brightly, like a star or a light
come into being or existence, or appear on the scene	be shiny, as if wet
appear as a character on stage or appear in a play, etc.
give a certain impression of being something or having a certain aspect
(of a proposition) seem to be true, probable, or apparent
present oneself formally, as before a (judicial) authority