litter lout vs litterbug

litter lout and litterbug both are nouns.

Word	Noun	Adjective	Verb	Adverb
litter lout	Yes	No	No	No
litterbug	Yes	No	No	No

As nouns, litter lout and litterbug are synonyms defined as:

litter lout and litterbug: a person who litters public places with refuse

Other synonyms of litter lout include litterer.

litter lout (noun)	litterbug (noun)
a person who litters public places with refuse	a person who litters public places with refuse