Analogy
similitude of relations between one thing and other. The thing to which the other is compared is preceded by to or with. When both are mentioned together they are connected by the word between.
In logic, the resemblance of relations, a meaning given to the word first by the mathematicians.
As more commonly used it is a resemblance of any kind on which an argument falling short of induction may be founded. If an invariable conjunction is made out between a property erty in the one case and a property in the other, the argument rises above analogy, and becomes an induction on a limited basis; but if no such conjunction has been made out, then the argument is one of analogy merely. Metaphor and allegory address the imagination, while analogy appeals to the reason. The former are founded on similarity of appearances, of effects, or of incidental circumstances; the latter is built upon more essential resemblances, which afford a proper basis for reasoning.
In biology, an analogy is the relation between parts which agree in function, ANALYSIS terfly, the tail of a whale and that of a fish.