complainer vs moaner

complainer and moaner both are nouns.

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

As nouns, complainer and moaner are synonyms defined as:

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

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

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