odontoid process vs appendage

odontoid process and appendage both are nouns.

Word	Noun	Adjective	Verb	Adverb
odontoid process	Yes	No	No	No
appendage	Yes	No	No	No

As nouns, appendage is a hypernym of odontoid process; that is, appendage is a word with a broader meaning than odontoid process:

odontoid process: a toothlike process at the back of 2nd vertebra of the neck
appendage: a natural prolongation or projection from a part of an organism either animal or plant

Other hypernyms of odontoid process include outgrowth, process.

odontoid process (noun)	appendage (noun)
a toothlike process at the back of 2nd vertebra of the neck	a part that is joined to something larger
	an external body part that projects from the body
	a natural prolongation or projection from a part of an organism either animal or plant