1. Related by blood; having a common ancestor.
2. Related in origin, as certain words in genetically related languages descended from the same ancestral root; for example, English name and Latin nōmen from Indo-European *n-men-.
3. Related or analogous in nature, character, or function.
1. One related by blood or origin with another, especially a person sharing an ancestor with another.
2. A word related to one in another language.
3. A sequence of university courses taken as an adjunct to a graduate degree program: earned an MA in linguistics with a cognate in computer science.
[Latin cognātus : co-, co- + gnātus, born, past participle of nāscī, to be born; see genə- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.