unseeable vs infrared

unseeable is not a noun while infrared is a noun.

Word	Noun	Adjective	Verb	Adverb
unseeable	No	Yes	No	No
infrared	Yes	Yes	No	No

unseeable (noun)	infrared (noun)
	the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range
	electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves

unseeable (adjective)	infrared (adjective)
impossible or nearly impossible to see; imperceptible by the eye	having or employing wavelengths longer than light but shorter than radio waves; lying outside the visible spectrum at its red end