# homology

CEFR C1 · Noun

Source: https://englishreference.com/word/homology
Updated: 2026-05-30

## Definition

a similarity between two things because they share a common origin or history. In biology, it means two different animals have the same body part because they are related.

For teachers: the condition of being similar in structure, function, or origin because of common ancestry. In mathematics, it refers to a relationship between two objects that preserves their essential properties.

## Examples

- The wings of a bat and a bird show structural homology.
- Biologists use homology to determine how different species are related by comparing their skeletal structures.
- While the specific functions of the limbs may have diverged through evolution, the underlying homology of the bones provides clear evidence of a shared vertebrate ancestor.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.