A-năl'ō-gy, n.
n. [Lat. analogia, Gr. ἀναλογία, from ἀνάλογος. See ANALOGOUS.]
Sense 1. An agreement or likeness between things in some circumstances or effects, when the things are otherwise entirely different. Thus, learning enlightens the mind, because it is to the mind what light is to the eye, enabling it to discover things before hidden.
☞ When both the things which have an analogy follow a preposition, that preposition must be between or betwixt; as, there is an analogy between plants and animals, or between customs. When one of the things precedes a verb, and the other follows, the preposition used must be to or with; as, a plant has some analogy to or with an animal. Analogy is not unfrequently used to denote mere similarity. But its specific meaning is a similarity of relations, and in this consists the difference between the argument from example and that from analogy. In the former, we argue from the mere similarity of two things; in the latter, from the similarity of their relations. Karslake.
Sense 2. (Geom.) Equality, proportion, or similarity of ratios. Hatton.
Sense 3. (Gram.) Conformity of words to the genius, structure, or general rules of a language; similarity of origin, inflection, or principle of pronunciation, and the like, as opposed to anomaly. Johnson.