overlap vs lappet

overlap and lappet both are nouns.

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

As nouns, lappet is a hyponym of overlap; that is, lappet is a word with a more specific, narrower meaning than overlap:

Other hyponyms of overlap include cuff, turnup, lapel.

overlap (noun)	lappet (noun)
a flap that lies over another part	medium-sized hairy moths; larvae are lappet caterpillars
the property of partial coincidence in time	a small lap on a garment or headdress
a representation of common ground between theories or phenomena	a fleshy wrinkled and often brightly colored fold of skin hanging from the neck or throat of certain birds (chickens and turkeys) or lizards

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