analogy

noun

1. 1.A relationship of resemblance or equivalence between two situations, people, or objects, especially when used as a basis for explanation or extrapolation.
2. 2.The proportion or the equality of ratios.
3. 3.(grammar) The correspondence of a word or phrase with the genius of a language, as learned from the manner in which its words and phrases are ordinarily formed; similarity of derivative or inflectional processes.