fog vs becloud

fog is a noun but becloud is not a noun.

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

As verbs, fog and becloud are synonyms defined as:

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

fog (noun)	becloud (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)	becloud (verb)
make less visible or unclear	make less visible or unclear