Definition of "homology" []

• The quality or condition of being homologous. (noun)
• A homologous relationship or correspondence. (noun)
• Chemistry The relation of the elements of a periodic family or group. (noun)
• Chemistry The relation of the organic compounds forming a homologous series. (noun)
• Mathematics A topological classification of configurations into distinct types that imposes an algebraic structure or hierarchy on families of geometric figures. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "a part or organ in a different animal; the determination of which homology indicates that such animals are constructed on a common type; when, for example, the correspondence of the basilar process of the human occipital bone with the distinct bone called 'basi-occipital' in a fish or crocodile is shown, the _special homology_ of that process is determined."
• "By the term homology he expresses the unity or identity of character between the bones so answering to one another in different animals."
• "Knowledge of homology is certainly very useful, can give us a good idea of the path of descent, and can constrain our hypotheses."