fug vs fogginess

fug and fogginess both are nouns.

Word	Noun	Adjective	Verb	Adverb
fug	Yes	No	No	No
fogginess	Yes	No	No	No

As nouns, fogginess is a hypernym of fug; that is, fogginess is a word with a broader meaning than fug:

fug: (British informal) an airless smoky smelly atmosphere
fogginess: an atmosphere in which visibility is reduced because of a cloud of some substance

Other hypernyms of fug include fog, murk, murkiness.

fug (noun)	fogginess (noun)
(British informal) an airless smoky smelly atmosphere	the quality of being indistinct and without sharp outlines
	an atmosphere in which visibility is reduced because of a cloud of some substance