fog vs overshadow

fog is a noun but overshadow is not a noun.

Word	Noun	Adjective	Verb	Adverb
fog	Yes	No	Yes	No
overshadow	No	No	Yes	No

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

fog (noun)	overshadow (noun)
confusion characterized by lack of clarity
droplets of water vapor suspended in the air near the ground
an atmosphere in which visibility is reduced because of a cloud of some substance

fog (verb)	overshadow (verb)
make less visible or unclear	cast a shadow upon
	be greater in significance than
	make appear small by comparison