malignant vs malignancy

malignant is not a noun while malignancy is a noun.

Word	Noun	Adjective	Verb	Adverb
malignant	No	Yes	No	No
malignancy	Yes	No	No	No

malignant (noun)	malignancy (noun)
	quality of being disposed to evil; intense ill will
	(medicine) a malignant state; progressive and resistant to treatment and tending to cause death

malignant (adjective)	malignancy (adjective)
dangerous to health; characterized by progressive and uncontrolled growth (especially of a tumor)