murmuring vs murmur

murmuring and murmur both are nouns.

Word	Noun	Adjective	Verb	Adverb
murmuring	Yes	Yes	No	No
murmur	Yes	No	Yes	No

As nouns, murmuring and murmur are synonyms defined as:

Other synonyms of murmuring include grumble, grumbling, mutter, muttering.

As nouns, murmuring and murmur are synonyms defined as:

murmuring and murmur: a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech

Other synonyms of murmuring include murmuration, mussitation, mutter, muttering.

murmuring (noun)	murmur (noun)
a complaint uttered in a low and indistinct tone	a complaint uttered in a low and indistinct tone
a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech	a schwa that is incidental to the pronunciation of a consonant
	a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
	an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves

murmuring (adjective)	murmur (adjective)
making a low continuous indistinct sound

murmuring (verb)	murmur (verb)
	speak softly or indistinctly
	make complaining remarks or noises under one's breath