mock turtleneck vs turtle

mock turtleneck and turtle both are nouns.

Word	Noun	Adjective	Verb	Adverb
mock turtleneck	Yes	No	No	No
turtle	Yes	No	Yes	No

As nouns, turtle is a hypernym of mock turtleneck; that is, turtle is a word with a broader meaning than mock turtleneck:

mock turtleneck: A sweater with a short turtleneck collar that does not fold down.
turtle: a sweater or jersey with a high close-fitting collar

Other hypernyms of mock turtleneck include polo-neck, turtleneck.

mock turtleneck (noun)	turtle (noun)
A sweater with a short turtleneck collar that does not fold down.	any of various aquatic and land reptiles having a bony shell and flipper-like limbs for swimming
	a sweater or jersey with a high close-fitting collar

mock turtleneck (verb)	turtle (verb)
	hunt for turtles, especially as an occupation
	overturn accidentally