tarnish vs fleck

tarnish and fleck both are nouns.

Word	Noun	Adjective	Verb	Adverb
tarnish	Yes	No	Yes	No
fleck	Yes	No	Yes	No

As verbs, fleck is a hypernym of tarnish; that is, fleck is a word with a broader meaning than tarnish:

tarnish: make dirty or spotty, as by exposure to air; also used metaphorically
fleck: make a spot or mark onto

Other hypernyms of tarnish include blob, blot, spot.

tarnish (noun)	fleck (noun)
discoloration of metal surface caused by oxidation	a small contrasting part of something
	a small fragment of something broken off from the whole

tarnish (verb)	fleck (verb)
make dirty or spotty, as by exposure to air; also used metaphorically	make a spot or mark onto