family-tree theory
[fam-uh-lee tree, fam-lee-]
noun Historical Linguistics.
a theory that describes language change in terms of genetically related languages developing in successive splits from a common parent language, such as Indo-European, as depicted by a family tree diagram.
Compare wave theory.
Origin of family-tree theory
First recorded in 1930–35
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019