a. Exercising the most power, control, or influence: the dominant nations during the Cold War.
b. Most abundant or conspicuous; predominant: "[The fireplaces'] shallow brick arches are a relief from the dominant squares and verticals of the windows and doors" (Stephen A. Kliment).
2. Higher; overlooking: dominant hills.
3. Tending to be stronger than its counterpart or used for the most important tasks or in the most pressing situations: Which is your dominant eye? Throw the ball with your dominant arm.
4. Genetics Of, relating to, or being an allele that produces the same phenotypic effect in heterozygotes as in homozygotes.
5. Ecology Of, relating to, or being a species that is most characteristic of an ecological community and usually determines the presence, abundance, and type of other species.
6. Music Relating to or based on the fifth tone of a diatonic scale.
1. Genetics A dominant allele or a trait produced by a dominant allele.
2. Ecology A dominant species.
3. Music The fifth tone of a diatonic scale.
[Middle English dominaunt, from Old French, from Latin domināns, dominant-, present participle of dominārī, to dominate; see DOMINATE.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.