fog vs haze over

fog is a noun but haze over is not a noun.

Word	Noun	Adjective	Verb	Adverb
fog	Yes	No	Yes	No
haze over	No	No	Yes	No

As verbs, fog and haze over are synonyms defined as:

Other synonyms of fog include becloud, befog, cloud, mist, obnubilate, obscure.

fog (noun)	haze over (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)	haze over (verb)
make less visible or unclear	make less visible or unclear