bull neck vs cervix

bull neck and cervix both are nouns.

Word	Noun	Adjective	Verb	Adverb
bull neck	Yes	No	No	No
cervix	Yes	No	No	No

As nouns, cervix is a hypernym of bull neck; that is, cervix is a word with a broader meaning than bull neck:

bull neck: a thick short powerful neck
cervix: the part of an organism (human or animal) that connects the head to the rest of the body

Other hypernyms of bull neck include neck.

bull neck (noun)	cervix (noun)
a thick short powerful neck	the part of an organism (human or animal) that connects the head to the rest of the body
	necklike opening to the uterus