ratio vs rational

ratio and rational both are nouns.

Word	Noun	Adjective	Verb	Adverb
ratio	Yes	No	No	No
rational	Yes	Yes	No	No

ratio (noun)	rational (noun)
the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree	an integer or a fraction
the relative magnitudes of two quantities (usually expressed as a quotient)

ratio (adjective)	rational (adjective)
	consistent with or based on or using reason
	capable of being expressed as a quotient of integers
	having its source in or being guided by the intellect (as distinguished from experience or emotion)
	of or associated with or requiring the use of the mind