free nerve ending vs skin

free nerve ending and skin both are nouns.

Word	Noun	Adjective	Verb	Adverb
free nerve ending	Yes	No	No	No
skin	Yes	No	Yes	No

free nerve ending (noun)	skin (noun)
microscopic sensory nerve endings in the skin that are not connected to any specific sensory receptor	body covering of a living animal
	an outer surface (usually thin)
	a bag serving as a container for liquids; it is made from the hide of an animal
	a natural protective body covering and site of the sense of touch
	the rind of a fruit or vegetable
	a member of any of several British or American groups consisting predominantly of young people who shave their heads; some engage in white supremacist and anti-immigrant activities and this leads to the perception that all skinheads are racist and violent
	a person whose head is bald or shaved
	a person's skin regarded as their life

free nerve ending (verb)	skin (verb)
	remove the skin from
	remove the bark of a tree
	bruise, cut, or injure the skin or the surface of
	climb awkwardly, as if by scrambling