grumble vs grumbler

grumble and grumbler both are nouns.

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

grumble (noun)	grumbler (noun)
a complaint uttered in a low and indistinct tone	a person given to excessive complaints and crying and whining
a loud low dull continuous noise

grumble (verb)	grumbler (verb)
make complaining remarks or noises under one's breath
show one's unhappiness or critical attitude
to utter or emit low dull rumbling sounds
make a low noise