overlapping vs overlap

overlapping and overlap both are nouns.

Word	Noun	Adjective	Verb	Adverb
overlapping	Yes	No	No	No
overlap	Yes	No	Yes	No

overlapping (noun)	overlap (noun)
covering with a design in which one element covers a part of another (as with tiles or shingles)	a flap that lies over another part
	the property of partial coincidence in time
	a representation of common ground between theories or phenomena

overlapping (verb)	overlap (verb)
	extend over and cover a part of
	coincide partially or wholly