intensify vs intensity

intensify is not a noun while intensity is a noun.

Word	Noun	Adjective	Verb	Adverb
intensify	No	No	Yes	No
intensity	Yes	No	No	No

intensify (noun)	intensity (noun)
	high level or degree; the property of being intense
	chromatic purity: freedom from dilution with white and hence vivid in hue
	the magnitude of sound (usually in a specified direction)
	the amount of energy transmitted (as by acoustic or electromagnetic radiation)

intensify (verb)	intensity (verb)
become more intense
make more intense, stronger, or more marked
increase in extent or intensity
make the chemically affected part of (a negative) denser or more opaque in order produce a stronger contrast between light and dark