arm vs elbow

arm and elbow both are nouns.

Word	Noun	Adjective	Verb	Adverb
arm	Yes	No	Yes	No
elbow	Yes	No	Yes	No

arm (noun)	elbow (noun)
the part of a garment that is attached at the armhole and that provides a cloth covering for the arm	the joint of a mammal or bird that corresponds to the human elbow
any instrument or instrumentality used in fighting or hunting	the part of a sleeve that covers the elbow joint
the part of an armchair or sofa that supports the elbow and forearm of a seated person	a sharp bend in a road or river
any projection that is thought to resemble a human arm	a length of pipe with a sharp bend in it
a human limb; technically the part of the superior limb between the shoulder and the elbow but commonly used to refer to the whole superior limb	hinge joint between the forearm and upper arm and the corresponding joint in the forelimb of a quadruped
a division of some larger or more complex organization

arm (verb)	elbow (verb)
prepare oneself for a military confrontation	shove one's elbow into another person's ribs
supply with arms	push one's way with the elbows