ETYM Greek, assenting, agreeing; homo the same + logos speech, discourse, proportion, legein to say, speak.
1. Corresponding or similar in position or structure or function or characteristics; especially derived from an organism of the same species.
2. (Biology) Having the same evolutionary origin but serving different functions.
In biology, a term describing an organ or structure possessed by members of different taxonomic groups (for example, species, genera, families, orders) that originally derived from the same structure in a common ancestor. The wing of a bat, the arm of a monkey, and the flipper of a seal are homologous because they all derive from the forelimb of an ancestral mammal.
Exactly or relatively corresponding in structure.