mock turtleneck vs turtleneck

mock turtleneck and turtleneck both are nouns.

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

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

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

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

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