extremity vs pincer

extremity and pincer both are nouns.

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

As nouns, pincer is a hyponym of extremity; that is, pincer is a word with a more specific, narrower meaning than extremity:

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

Other hyponyms of extremity include chelicera, mouthpart, fang, chela, claw, nipper, parapodium, fin, pleopod, swimmeret, limb, dactyl, digit.

extremity (noun)	pincer (noun)
an external body part that projects from the body	a grasping structure on the limb of a crustacean or other arthropods
that part of a limb that is farthest from the torso	a hand tool for holding consisting of a compound lever for grasping
the outermost or farthest region or point
the greatest or utmost degree
an extreme condition or state (especially of adversity or disease)