sniveller vs complainer

sniveller and complainer both are nouns.

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

As nouns, sniveller and complainer are synonyms defined as:

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

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

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