nipper vs extremity

nipper and extremity both are nouns.

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

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

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

Other hypernyms of nipper include appendage, member.

nipper (noun)	extremity (noun)
a grasping structure on the limb of a crustacean or other arthropods	an external body part that projects from the body
a young person of either sex	that part of a limb that is farthest from the torso
	the outermost or farthest region or point
	the greatest or utmost degree
	an extreme condition or state (especially of adversity or disease)