A figure of speech in which two words connected by a conjunction are used to express a single notion that would normally be expressed by an adjective and a substantive, such as grace and favor instead of gracious favor.
[Late Latin, from Greek hen dia duoin, one by means of two : hen, neuter of heis, one; see sem-1 in the Appendix of Indo-European roots + dia, through + duoin, genitive of duo, two; see dwo- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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.