dom·i·nant 
(dŏmə-nənt)
(dŏmə-nənt)adj.
1.
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.
n.
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.]
domi·nant·ly adv.