crank vs unstable

crank is a noun but unstable is not a noun.

Word	Noun	Adjective	Verb	Adverb
crank	Yes	Yes	Yes	No
unstable	No	Yes	No	No

crank (noun)	unstable (noun)
a hand tool consisting of a rotating shaft with parallel handle
an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant
a bad-tempered person
a whimsically eccentric person

crank (adjective)	unstable (adjective)
(used of boats) inclined to heel over easily under sail	lacking stability or fixity or firmness
	subject to change; variable
	suffering from severe mental illness
	disposed to psychological variability
	highly or violently reactive
	affording no ease or reassurance