fairness vs unjust

fairness is a noun but unjust is not a noun.

Word	Noun	Adjective	Verb	Adverb
fairness	Yes	No	No	No
unjust	No	Yes	No	No

fairness (noun)	unjust (noun)
conformity with rules or standards
the property of having a naturally light complexion
the quality of being good looking and attractive
ability to make judgments free from discrimination or dishonesty

fairness (adjective)	unjust (adjective)
	violating principles of justice
	not equitable or fair
	not fair; marked by injustice or partiality or deception