infectious vs infection

infectious is not a noun while infection is a noun.

Word	Noun	Adjective	Verb	Adverb
infectious	No	Yes	No	No
infection	Yes	No	No	No

infectious (noun)	infection (noun)
	moral corruption or contamination
	(international law) illegality that taints or contaminates a ship or cargo rendering it liable to seizure
	the communication of an attitude or emotional state among a number of people
	an incident in which an infectious disease is transmitted
	(medicine) the invasion of the body by pathogenic microorganisms and their multiplication which can lead to tissue damage and disease
	(phonetics) the alteration of a speech sound under the influence of a neighboring sound
	the pathological state resulting from the invasion of the body by pathogenic microorganisms

infectious (adjective)	infection (adjective)
easily spread
of or relating to infection
caused by infection or capable of causing infection