infection vs infectious

infection is a noun but infectious is not a noun.

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

infection (noun)	infectious (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

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