Pronunciation: (dom'u-nunt),[key] —adj. 1. ruling, governing, or controlling; having or exerting authority or influence: dominant in the chain of command. 2. occupying or being in a commanding or elevated position.
3. predominant; main; major; chief: Corn is the dominant crop of Iowa. 4. Genetics.of or pertaining to a dominant.
5. Music.pertaining to or based on the dominant: the dominant chord.
—n. 1. Genetics. a. the one of a pair of alternative alleles that masks the effect of the other when both are present in the same cell or organism.
b. the trait or character determined by such an allele. Cf. recessive (defs. 4, 5).
2. Music.the fifth tone of a diatonic scale.
3. Ecol.any of one or more types of plants, or sometimes animals, that by virtue of abundance, size, or habits exert so important an influence on the conditions of an area as to determine, to a great extent, what other organisms can live there.