forearm vs radius

forearm and radius both are nouns.

Word	Noun	Adjective	Verb	Adverb
forearm	Yes	No	Yes	No
radius	Yes	No	No	No

forearm (noun)	radius (noun)
the part of the superior limb between the elbow and the wrist	support consisting of a radial member of a wheel joining the hub to the rim
	the length of a line segment between the center and circumference of a circle or sphere
	the outer and slightly shorter of the two bones of the human forearm
	a circular region whose area is indicated by the length of its radius
	a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)

forearm (verb)	radius (verb)
arm in advance of a confrontation