appendage vs extremity

appendage and extremity both are nouns.

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

As nouns, appendage and extremity are synonyms defined as:

appendage and extremity: an external body part that projects from the body

Other synonyms of appendage include member.

appendage (noun)	extremity (noun)
a part that is joined to something larger	an external body part that projects from the body
an external body part that projects from the body	that part of a limb that is farthest from the torso
a natural prolongation or projection from a part of an organism either animal or plant	the outermost or farthest region or point
	the greatest or utmost degree
	an extreme condition or state (especially of adversity or disease)