Peter Pan collar vs neckband

Peter Pan collar and neckband both are nouns.

Word	Noun	Adjective	Verb	Adverb
Peter Pan collar	Yes	No	No	No
neckband	Yes	No	No	No

As nouns, neckband is a hypernym of Peter Pan collar; that is, neckband is a word with a broader meaning than Peter Pan collar:

Other hypernyms of Peter Pan collar include collar.

Peter Pan collar (noun)	neckband (noun)
a flat collar with rounded ends that meet in front	a band that fits around the neck and is usually folded over
	necklace that fits tightly around a woman's neck
	a band around the collar of a garment