pincer vs appendage

pincer and appendage both are nouns.

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

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

pincer: 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 pincer include extremity, member.

pincer (noun)	appendage (noun)
a grasping structure on the limb of a crustacean or other arthropods	a part that is joined to something larger
a hand tool for holding consisting of a compound lever for grasping	an external body part that projects from the body
	a natural prolongation or projection from a part of an organism either animal or plant