An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) A similarity or comparability between two things.
2) Math.: A general similarity between two problems or methods. Analogy is used to infer new theorems from existing ones. Hypotheses based on analogy must still be proved.
3) Logic: A form of reasoning which asserts that if two or more entities are similar in one or more respects, then they would be similar in other respects.
4) Biology: An analogous relationship.
5) Linguistics: The process by which a word or form is either created or changed according to existing patterns in the language.

M.E., from O.Fr. analogie or directly from L. analogia, from Gk. analogia "proportion," from → ana- "upon, according to" + logos "ratio; word, speech, reckoning," → -logy.