neck opening vs collar

neck opening and collar both are nouns.

Word	Noun	Adjective	Verb	Adverb
neck opening	Yes	No	No	No
collar	Yes	No	Yes	No

neck opening (noun)	collar (noun)
an opening in a garment for the neck of the wearer; a part of the garment near the wearer's neck	the act of apprehending (especially apprehending a criminal)
	a figurative restraint
	a band that fits around the neck and is usually folded over
	necklace that fits tightly around a woman's neck
	a band of leather or rope that is placed around an animal's neck as a harness or to identify it
	the stitching that forms the rim of a shoe or boot
	a short ring fastened over a rod or shaft to limit, guide, or secure a machine part
	anything worn or placed about the neck
	(zoology) an encircling band or marking around the neck of any animal