mitt vs extremity

mitt and extremity both are nouns.

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

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

mitt (noun)	extremity (noun)
the handwear used by fielders in playing baseball	an external body part that projects from the body
the (prehensile) extremity of the superior limb	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)