nipper vs appendage

nipper and appendage both are nouns.

Word	Noun	Adjective	Verb	Adverb
nipper	Yes	No	No	No
appendage	Yes	No	No	No

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

nipper: a grasping structure on the limb of a crustacean or other arthropods
appendage: an external body part that projects from the body

Other hypernyms of nipper include extremity, member.

nipper (noun)	appendage (noun)
a grasping structure on the limb of a crustacean or other arthropods	a part that is joined to something larger
a young person of either sex	an external body part that projects from the body
	a natural prolongation or projection from a part of an organism either animal or plant