sloven vs litterbug

sloven and litterbug both are nouns.

Word	Noun	Adjective	Verb	Adverb
sloven	Yes	No	No	No
litterbug	Yes	No	No	No

As nouns, litterbug is a hyponym of sloven; that is, litterbug is a word with a more specific, narrower meaning than sloven:

Other hyponyms of sloven include litter lout, litterer, slattern, slovenly woman, slut, trollop.

sloven (noun)	litterbug (noun)
a coarse obnoxious person	a person who litters public places with refuse