flapping vs fluttering

flapping and fluttering both are nouns.

Word	Noun	Adjective	Verb	Adverb
flapping	Yes	No	No	No
fluttering	Yes	No	No	No

As nouns, flapping and fluttering are synonyms defined as:

Other synonyms of flapping include flap, flutter.

flapping (noun)	fluttering (noun)
the motion made by flapping up and down	the motion made by flapping up and down