odds vs ratio

odds and ratio both are nouns.

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

As nouns, ratio is a hypernym of odds; that is, ratio is a word with a broader meaning than odds:

odds: the ratio by which one better's wager is greater than that of another
ratio: the relative magnitudes of two quantities (usually expressed as a quotient)

odds (noun)	ratio (noun)
the likelihood of a thing occurring rather than not occurring	the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree
the ratio by which one better's wager is greater than that of another	the relative magnitudes of two quantities (usually expressed as a quotient)