DOMINANT, in music, the fifth degree of the diatonic scale, e.g., G in the key of C ; A in that of D, and so on; so called from its exceptional influence and importance in relation to the tonic, or key-note, and the harmony in general.
Dominant was used by Mendel to describe a biological character which manifests itself, as opposed to a recessive character, which remains latent (see MENDELISM).