human elbow vs elbow joint

human elbow and elbow joint both are nouns.

Word	Noun	Adjective	Verb	Adverb
human elbow	Yes	No	No	No
elbow joint	Yes	No	No	No

As nouns, human elbow and elbow joint are synonyms defined as:

human elbow and elbow joint: hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped

Other synonyms of human elbow include articulatio cubiti, cubital joint, cubitus, elbow.

human elbow (noun)	elbow joint (noun)
hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped	hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped