sniveller vs grumbler

sniveller and grumbler both are nouns.

Word	Noun	Adjective	Verb	Adverb
sniveller	Yes	No	No	No
grumbler	Yes	No	No	No

As nouns, sniveller and grumbler are synonyms defined as:

sniveller and grumbler: a person given to excessive complaints and crying and whining

Other synonyms of sniveller include bellyacher, complainer, crybaby, moaner, squawker, whiner.

sniveller (noun)	grumbler (noun)
a person given to excessive complaints and crying and whining	a person given to excessive complaints and crying and whining